moved parts of doc to deprecated/doc

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diff --git a/doc/gf-tutorial.txt b/doc/gf-tutorial.txt
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@@ -1,5022 +0,0 @@
-Grammatical Framework Tutorial
-Aarne Ranta
-Version 3.1.2, November 2008
-
-
-% NOTE: this is a txt2tags file.
-% Create a tex file from this file using:
-% txt2tags --toc -ttex gf-tutorial.txt
-
-%!target:html
-%!encoding: iso-8859-1
-
-%!postproc(tex) : "\\subsection\*" "\\newslide"
-%!preproc(tex): "#NEW" ""
-%!postproc(html): #NEW <!-- NEW -->
-
-
-
-%!postproc(html): #OVERVIEW <h2>Overview</h2>
-
-%%!postproc(tex): "section\*" "section"
-
-%!postproc(tex): "\\documentclass{article}" ""
-
-%!postproc(tex): "subsection\*" "section"
-%!postproc(tex): "section\*" "chapter"
-
-%!postproc(tex): "textbf{Exercise}" "exercise"
-%!postproc(tex): "textbf" "keywrd"
-
-%!postproc(html): #BCEN <center>
-%!postproc(html): #ECEN </center>
-
-%!postproc(tex): #BCEN "begin{center}"
-%!postproc(tex): #ECEN "end{center}"
-
-%!postproc(tex): #BEQU "bequ"
-%!postproc(tex): #ENQU "enqu"
-%!postproc(html): #BEQU "<center>"
-%!postproc(html): #ENQU "</center>"
-
-%!preproc(html): #EDITORPNG [quick-editor.png]
-%!preproc(tex):  #EDITORPNG [10lang-small.png]
-
-%!preproc(html): #LOGOPNG [Logos/gf0.png]
-%!preproc(tex):  #LOGOPNG [Logos/gf0.png]
-
-
-%!postproc(tex): #PARTone "part{Tutorial}"
-%!postproc(tex): #PARTtwo "part{Applications of Grammars}"
-%!postproc(tex): #PARTfour "part{Advanced Grammar Writing}"
-%!postproc(tex): #PARTthree "part{Reference Manual}"
-
-%%!postproc(tex): #PARTbnf "include{DocGF}"
-%!postproc(tex): #PARTquickref "chapter{Quick Reference}"
-%!postproc(tex): #twocolumn ""%twocolumn"
-%!postproc(tex): #newpage "newpage"
-%!postproc(tex): #smallsize "small"
-%!postproc(tex): #normalsize "normalsize"
-%!postproc(tex): #startappendix "appendix"
-
-
-%!postproc(tex): #indexYACC "index{YACC}"
-
-%!postproc(tex): #MYTREE "input{mytree}"
-%!preproc(html): #MYTREE [mytree.png]
-%!postproc(tex): #FOODMARKET "input{foodmarket}"
-%!preproc(html): #FOODMARKET [foodmarket.png]
-%!postproc(tex): #CATEGORIES "input{categories}"
-%!preproc(html): #CATEGORIES [categories.png]
-
-%!postproc(tex): #Syntaxpic "input{Syntax}"
-%!postproc(tex): #Germanpic "input{German}"
-
-%!postproc(tex): #REFERENCES "input{references}"
-
-%!postproc(tex): #FORMULAone "input{FORMULAone}"
-
-%!postproc(tex): #SETLENGTHS "input{SETLENGTHS}"
-
-%!postproc(tex): #PRINTINDEX "printindex"
-
-%!postproc(tex): #Lchaptwo "label{chaptwo}"
-%!postproc(tex): #Rchaptwo "chref{chaptwo}"
-%!postproc(html): #Lchaptwo <a name="chaptwo"></a>
-%!postproc(html): #Rchaptwo <a href="#chaptwo">Lesson 1</a>
-
-%!postproc(tex): #Lchapthree "label{chapthree}"
-%!postproc(tex): #Rchapthree "chref{chapthree}"
-%!postproc(html): #Lchapthree <a name="chapthree"></a>
-%!postproc(html): #Rchapthree <a href="#chapthree">Lesson 2</a>
-
-%!postproc(tex): #Lchapfour "label{chapfour}"
-%!postproc(tex): #Rchapfour "chref{chapfour}"
-%!postproc(html): #Lchapfour <a name="chapfour"></a>
-%!postproc(html): #Rchapfour <a href="#chaptwo">Lesson 3</a>
-
-%!postproc(tex): #Lchapfive "label{chapfive}"
-%!postproc(tex): #Rchapfive "chref{chapfive}"
-%!postproc(html): #Lchapfive <a name="chapfive"></a>
-%!postproc(html): #Rchapfive <a href="#chapfive">Lesson 4</a>
-
-%!postproc(tex): #Lchapsix "label{chapsix}"
-%!postproc(tex): #Rchapsix "chref{chapsix}"
-%!postproc(html): #Lchapsix <a name="chapsix"></a>
-%!postproc(html): #Rchapsix <a href="#chapsix">Lesson 5</a>
-
-%!postproc(tex): #Lchapseven "label{chapseven}"
-%!postproc(tex): #Rchapseven "chref{chapseven}"
-%!postproc(html): #Lchapseven <a name="chapseven"></a>
-%!postproc(html): #Rchapseven <a href="#chapseven">Lesson 6</a>
-
-%!postproc(tex): #Lchapeight "label{chapeight}"
-%!postproc(tex): #Rchapeight "chref{chapeight}"
-%!postproc(html): #Lchapeight <a name="chapeight"></a>
-%!postproc(html): #Rchapeight <a href="#chapeight">Lesson 7</a>
-
-
-%2.7.2
-%!postproc(tex): #Lsecjment "label{secjment}"
-%!postproc(tex): #Rsecjment "sref{secjment}"
-%!postproc(html): #Lsecjment <a name="secjment"></a>
-%!postproc(html): #Rsecjment <a href="#secjment">here</a>
-
-%3.4
-%!postproc(tex): #Lsecanitalian "label{secanitalian}"
-%!postproc(tex): #Rsecanitalian "sref{secanitalian}"
-%!postproc(html): #Lsecanitalian <a name="secanitalian"></a>
-%!postproc(html): #Rsecanitalian <a href="#secanitalian">here</a>
-
-%3.6.1
-%!postproc(tex): #Lsectreebank "label{sectreebank}"
-%!postproc(tex): #Rsectreebank "sref{sectreebank}"
-%!postproc(html): #Lsectreebank <a name="sectreebank"></a>
-%!postproc(html): #Rsectreebank <a href="#sectreebank">here</a>
-
-
-%3.6.4
-%!postproc(tex): #Lsecediting "label{secediting}"
-%!postproc(tex): #Rsecediting "sref{secediting}"
-%!postproc(html): #Lsecediting <a name="secediting"></a>
-%!postproc(html): #Rsecediting <a href="#secediting">here</a>
-
-
-%3.9.5
-%!postproc(tex): #Lsecpartapp "label{secpartapp}"
-%!postproc(tex): #Rsecpartapp "sref{secpartapp}"
-%!postproc(html): #Lsecpartapp <a name="secpartapp"></a>
-%!postproc(html): #Rsecpartapp <a href="#secpartapp">here</a>
-
-%3.10
-%!postproc(tex): #Lsecarchitecture "label{secarchitecture}"
-%!postproc(tex): #Rsecarchitecture "sref{secarchitecture}"
-%!postproc(html): #Lsecarchitecture <a name="secarchitecture"></a>
-%!postproc(html): #Rsecarchitecture <a href="#secarchitecture">here</a>
-
-%4.6
-%!postproc(tex): #Lsecinflection "label{secinflection}"
-%!postproc(tex): #Rsecinflection "sref{secinflection}"
-%!postproc(html): #Lsecinflection <a name="secinflection"></a>
-%!postproc(html): #Rsecinflection <a href="#secinflection">here</a>
-
-%4.7
-%!postproc(tex): #Lsecitalian "label{secitalian}"
-%!postproc(tex): #Rsecitalian "sref{secitalian}"
-%!postproc(html): #Lsecitalian <a name="secitalian"></a>
-%!postproc(html): #Rsecitalian <a href="#secitalian">here</a>
-
-%4.10.2
-%!postproc(tex): #Lsecmatching "label{secmatching}"
-%!postproc(tex): #Rsecmatching "sref{secmatching}"
-%!postproc(html): #Lsecmatching <a name="secmatching"></a>
-%!postproc(html): #Rsecmatching <a href="#secmatching">here</a>
-
-%5.2
-%!postproc(tex): #Lseclexical "label{seclexical}"
-%!postproc(tex): #Rseclexical "sref{seclexical}"
-%!postproc(html): #Lseclexical <a name="seclexical"></a>
-%!postproc(html): #Rseclexical <a href="#seclexical">here</a>
-
-%5.4
-%!postproc(tex): #Lsecenglish "label{secenglish}"
-%!postproc(tex): #Rsecenglish "sref{secenglish}"
-%!postproc(html): #Lsecenglish <a name="secenglish"></a>
-%!postproc(html): #Rsecenglish <a href="#secenglish">here</a>
-
-%5.5
-%!postproc(tex): #Lsecfunctor "label{secfunctor}"
-%!postproc(tex): #Rsecfunctor "sref{secfunctor}"
-%!postproc(html): #Lsecfunctor <a name="secfunctor"></a>
-%!postproc(html): #Rsecfunctor <a href="#secfunctor">here</a>
-
-%5.6
-%!postproc(tex): #Lsecinterface "label{secinterface}"
-%!postproc(tex): #Rsecinterface "sref{secinterface}"
-%!postproc(html): #Lsecinterface <a name="secinterface"></a>
-%!postproc(html): #Rsecinterface <a href="#secinterface">here</a>
-
-%5.11
-%!postproc(tex): #Lsecbrowsing "label{secbrowsing}"
-%!postproc(tex): #Rsecbrowsing "sref{secbrowsing}"
-%!postproc(html): #Lsecbrowsing <a name="secbrowsing"></a>
-%!postproc(html): #Rsecbrowsing <a href="#secbrowsing">here</a>
-
-%5.12
-%!postproc(tex): #Lsecextended "label{secextended}"
-%!postproc(tex): #Rsecextended "sref{secextended}"
-%!postproc(html): #Lsecextended <a name="secextended"></a>
-%!postproc(html): #Rsecextended <a href="#secextended">here</a>
-
-%5.13
-%!postproc(tex): #Lsectense "label{sectense}"
-%!postproc(tex): #Rsectense "sref{sectense}"
-%!postproc(html): #Lsectense <a name="sectense"></a>
-%!postproc(html): #Rsectense <a href="#sectense">here</a>
-
-%5.14.2
-%!postproc(tex): #Lseclock "label{seclock}"
-%!postproc(tex): #Rseclock "sref{seclock}"
-%!postproc(html): #Lseclock <a name="seclock"></a>
-%!postproc(html): #Rseclock <a href="#seclock">here</a>
-
-%6.2
-%!postproc(tex): #Lsecsmarthouse "label{secsmarthouse}"
-%!postproc(tex): #Rsecsmarthouse "sref{secsmarthouse}"
-%!postproc(html): #Lsecsmarthouse <a name="secsmarthouse"></a>
-%!postproc(html): #Rsecsmarthouse <a href="#secsmarthouse">here</a>
-
-%6.3
-%!postproc(tex): #Lsecpolymorphic "label{secpolymorphic}"
-%!postproc(tex): #Rsecpolymorphic "sref{secpolymorphic}"
-%!postproc(html): #Lsecpolymorphic <a name="secpolymorphic"></a>
-%!postproc(html): #Rsecpolymorphic <a href="#secpolymorphic">here</a>
-
-%6.7
-%!postproc(tex): #Lsecbinding "label{secbinding}"
-%!postproc(tex): #Rsecbinding "sref{secbinding}"
-%!postproc(html): #Lsecbinding <a name="secbinding"></a>
-%!postproc(html): #Rsecbinding <a href="#secbinding">here</a>
-
-
-%6.8
-%!postproc(tex): #Lsecdefdef "label{secdefdef}"
-%!postproc(tex): #Rsecdefdef "sref{secdefdef}"
-%!postproc(html): #Lsecdefdef <a name="secdefdef"></a>
-%!postproc(html): #Rsecdefdef <a href="#secdefdef">here</a>
-
-%7.2
-%!postproc(tex): #Lseclexing "label{seclexing}"
-%!postproc(tex): #Rseclexing "sref{seclexing}"
-%!postproc(html): #Lseclexing <a name="seclexing"></a>
-%!postproc(html): #Rseclexing <a href="#seclexing">here</a>
-
-%7.3
-%!postproc(tex): #Lsecprecedence "label{secprecedence}"
-%!postproc(tex): #Rsecprecedence "sref{secprecedence}"
-%!postproc(html): #Lsecprecedence <a name="secprecedence"></a>
-%!postproc(html): #Rsecprecedence <a href="#secprecedence">here</a>
-
-%8.3.4
-%!postproc(tex): #Lsecmathprogram "label{secmathprogram}"
-%!postproc(tex): #Rsecmathprogram "sref{secmathprogram}"
-%!postproc(html): #Lsecmathprogram <a name="secmathprogram"></a>
-%!postproc(html): #Rsecmathprogram <a href="#secmathprogram">here</a>
-
-
-
-
-
-
-%!postproc(tex): #APPENDIX "appendix"
-%!postproc(tex): #CHAPTER "chapter{The GF Programming Language}"
-%!postproc(tex): #TOC "tableofcontents"
-
-%!postproc(tex): #BECE "begin{center}"
-%!postproc(tex): #ENCE "end{center}"
-%!postproc(tex): "subsection\*" "section"
-%!postproc(tex): "section\*" "chapter"
-%%!postproc(tex): "paragraph\{\}\\bf" "subsubsection"
-
-%!postproc(tex): #PARTbnf "input{RefDocGF.tex}"
-%!preproc(html): #PARTbnf %!include: RefDocGF.txt
-
-%!postproc(tex): "textbf" "keywrd"
-%!postproc(tex): #PRINTINDEX "printindex"
-%!preproc(html): #PRINTINDEX "" 
-
-%!postproc(tex): #sugar "sugar"
-%!postproc(tex): #comput "computes"
-
-%!postproc(tex): #Aone "subscr{A}{1}"
-%!postproc(tex): #Aen "subscr{A}{n}"
-%!postproc(tex): #Aii "subscr{A}{i}"
-%!postproc(tex): #aone "subscr{a}{1}"
-%!postproc(tex): #anone "subscr{a}{n-1}"
-%!postproc(tex): #aen "subscr{a}{n}"
-%!postproc(tex): #Bone "subscr{B}{1}"
-%!postproc(tex): #Bem "subscr{B}{m}"
-%!postproc(tex): #Ben "subscr{B}{n}"
-%!postproc(tex): #Cone "subscr{C}{1}"
-%!postproc(tex): #Cen "subscr{C}{n}"
-%!postproc(tex): #Cii "subscr{C}{i}"
-%!postproc(tex): #fone "subscr{f}{1}"
-%!postproc(tex): #fen "subscr{f}{n}"
-%!postproc(tex): #Gone "subscr{G}{1}"
-%!postproc(tex): #Gen "subscr{G}{n}"
-%!postproc(tex): #pone "subscr{p}{1}"
-%!postproc(tex): #pem "subscr{p}{m}"
-%!postproc(tex): #pen "subscr{p}{n}"
-%!postproc(tex): #pii "subscr{p}{i}"
-%!postproc(tex): #rii "subscr{r}{i}"
-%!postproc(tex): #rone "subscr{r}{1}"
-%!postproc(tex): #ren "subscr{r}{n}"
-%!postproc(tex): #sii "subscr{s}{i}"
-%!postproc(tex): #sone "subscr{s}{1}"
-%!postproc(tex): #sen "subscr{s}{n}"
-%!postproc(tex): #Tone "subscr{T}{1}"
-%!postproc(tex): #Ten "subscr{T}{n}"
-%!postproc(tex): #tone "subscr{t}{1}"
-%!postproc(tex): #tem "subscr{t}{m}"
-%!postproc(tex): #ten "subscr{t}{n}"
-%!postproc(tex): #tii "subscr{t}{i}"
-%!postproc(tex): #Vone "subscr{V}{1}"
-%!postproc(tex): #Ven "subscr{V}{n}"
-%!postproc(tex): #Vii "subscr{V}{i}"
-%!postproc(tex): #xnone "subscr{x}{n-1}"
-%!postproc(tex): #xone "subscr{x}{1}"
-%!postproc(tex): #xen "subscr{x}{n}"
-%!postproc(tex): #xii "subscr{x}{i}"
-%!postproc(tex): #yone "subscr{y}{1}"
-%!postproc(tex): #yem "subscr{y}{m}"
-%!postproc(tex): #zone "subscr{z}{1}"
-%!postproc(tex): #zem "subscr{z}{m}"
-
-%%% undo the effect for these links in the synopsis
-%!postproc(tex): "subscr\{G\}\{n\}der" "#Gender"
-%!postproc(tex): "subscr\{T\}\{n\}se" "#Tense"
-
-
-%%!target:html
-%!postproc(html): #APPENDIX ""
-%!postproc(html): #CHAPTER ""
-%!postproc(html): #TOC ""
-
-%!postproc(html): #BECE "<center>"
-%!postproc(html): #ENCE "</center>"
-%%!postproc(html): "subsection\*" "section"
-%%!postproc(html): "section\*" "chapter"
-%%!preproc(html): #PARTbnf "[BNF Grammar of GF RefDocGF.html]"
-
-%!postproc(html): #sugar "==="
-%!postproc(html): #comput "==>"
-
-%!postproc(html): #Aone "<i>A</i><sub>1</sub>"
-%!postproc(html): #Aen "<i>A</i><sub>n</sub>"
-%!postproc(html): #Aii "<i>A</i><sub>i</sub>"
-%!postproc(html): #aone "<i>a</i><sub>1</sub>"
-%!postproc(html): #anone "<i>a</i><sub>n-1</sub>"
-%!postproc(html): #aen "<i>a</i><sub>n</sub>"
-%!postproc(html): #Bone "<i>B</i><sub>1</sub>"
-%!postproc(html): #Bem "<i>B</i><sub>m</sub>"
-%!postproc(html): #Ben "<i>B</i><sub>n</sub>"
-%!postproc(html): #Cone "<i>C</i><sub>1</sub>"
-%!postproc(html): #Cen "<i>C</i><sub>n</sub>"
-%!postproc(html): #Cii "<i>C</i><sub>i</sub>"
-%!postproc(html): #fone "<i>f</i><sub>1</sub>"
-%!postproc(html): #fen "<i>f</i><sub>n</sub>"
-%!postproc(html): #Gone "<i>G</i><sub>1</sub>"
-%!postproc(html): #Gen "<i>G</i><sub>n</sub>"
-%!postproc(html): #pone "<i>p</i><sub>1</sub>"
-%!postproc(html): #pem "<i>p</i><sub>m</sub>"
-%!postproc(html): #pen "<i>p</i><sub>n</sub>"
-%!postproc(html): #pii "<i>p</i><sub>i</sub>"
-%!postproc(html): #rii "<i>r</i><sub>i</sub>"
-%!postproc(html): #rone "<i>r</i><sub>1</sub>"
-%!postproc(html): #ren "<i>r</i><sub>n</sub>"
-%!postproc(html): #sii "<i>s</i><sub>i</sub>"
-%!postproc(html): #sone "<i>s</i><sub>1</sub>"
-%!postproc(html): #sen "<i>s</i><sub>n</sub>"
-%!postproc(html): #Tone "<i>T</i><sub>1</sub>"
-%!postproc(html): #Ten "<i>T</i><sub>n</sub>"
-%!postproc(html): #tone "<i>t</i><sub>1</sub>"
-%!postproc(html): #tem "<i>t</i><sub>m</sub>"
-%!postproc(html): #ten "<i>t</i><sub>n</sub>"
-%!postproc(html): #tii "<i>t</i><sub>i</sub>"
-%!postproc(html): #Vone "<i>V</i><sub>1</sub>"
-%!postproc(html): #Ven "<i>V</i><sub>n</sub>"
-%!postproc(html): #Vii "<i>V</i><sub>i</sub>"
-%!postproc(html): #xnone "<i>x</i><sub>n-1</sub>"
-%!postproc(html): #xone "<i>x</i><sub>1</sub>"
-%!postproc(html): #xen "<i>x</i><sub>n</sub>"
-%!postproc(html): #xii "<i>x</i><sub>i</sub>"
-%!postproc(html): #yone "<i>y</i><sub>1</sub>"
-%!postproc(html): #yem "<i>y</i><sub>m</sub>"
-%!postproc(html): #zone "<i>z</i><sub>1</sub>"
-%!postproc(html): #zem "<i>z</i><sub>m</sub>"
-
-
-%!postproc(tex): #Lpatternmatching "label{patternmatching}"
-%!postproc(tex): #Rpatternmatching "sref{patternmatching}"
-%!postproc(html): #Lpatternmatching <a name="patternmatching"></a>
-%!postproc(html): #Rpatternmatching <a href="#patternmatching">here</a>
-
-%!postproc(tex): #Lcatjudgements "label{catjudgements}"
-%!postproc(tex): #Rcatjudgements "sref{catjudgements}"
-%!postproc(html): #Lcatjudgements <a name="catjudgements"></a>
-%!postproc(html): #Rcatjudgements <a href="#catjudgements">here</a>
-
-%!postproc(tex): #Lcnctypes "label{cnctypes}"
-%!postproc(tex): #Rcnctypes "sref{cnctypes}"
-%!postproc(html): #Lcnctypes <a name="cnctypes"></a>
-%!postproc(html): #Rcnctypes <a href="#cnctypes">here</a>
-
-%!postproc(tex): #Lcompleteness "label{completeness}"
-%!postproc(tex): #Rcompleteness "sref{completeness}"
-%!postproc(html): #Lcompleteness <a name="completeness"></a>
-%!postproc(html): #Rcompleteness <a href="#completeness">here</a>
-
-%!postproc(tex): #Lcontexts "label{contexts}"
-%!postproc(tex): #Rcontexts "sref{contexts}"
-%!postproc(html): #Lcontexts <a name="contexts"></a>
-%!postproc(html): #Rcontexts <a href="#contexts">here</a>
-
-%!postproc(tex): #Lconversions "label{conversions}"
-%!postproc(tex): #Rconversions "sref{conversions}"
-%!postproc(html): #Lconversions <a name="conversions"></a>
-%!postproc(html): #Rconversions <a href="#conversions">here</a>
-
-%!postproc(tex): #Lexpressions "label{expressions}"
-%!postproc(tex): #Rexpressions "sref{expressions}"
-%!postproc(html): #Lexpressions <a name="expressions"></a>
-%!postproc(html): #Rexpressions <a href="#expressions">here</a>
-
-%!postproc(tex): #Lflagvalues "label{flagvalues}"
-%!postproc(tex): #Rflagvalues "sref{flagvalues}"
-%!postproc(html): #Lflagvalues <a name="flagvalues"></a>
-%!postproc(html): #Rflagvalues <a href="#flagvalues">here</a>
-
-%!postproc(tex): #Lfunctionelimination "label{functionelimination}"
-%!postproc(tex): #Rfunctionelimination "sref{functionelimination}"
-%!postproc(html): #Lfunctionelimination <a name="functionelimination"></a>
-%!postproc(html): #Rfunctionelimination <a href="#functionelimination">here</a>
-
-%!postproc(tex): #Lfunctiontype "label{functiontype}"
-%!postproc(tex): #Rfunctiontype "sref{functiontype}"
-%!postproc(html): #Lfunctiontype <a name="functiontype"></a>
-%!postproc(html): #Rfunctiontype <a href="#functiontype">here</a>
-
-%!postproc(tex): #Lgluing "label{gluing}"
-%!postproc(tex): #Rgluing "sref{gluing}"
-%!postproc(html): #Lgluing <a name="gluing"></a>
-%!postproc(html): #Rgluing <a href="#gluing">here</a>
-
-%!postproc(tex): #LHOAS "label{HOAS}"
-%!postproc(tex): #RHOAS "sref{HOAS}"
-%!postproc(html): #LHOAS <a name="HOAS"></a>
-%!postproc(html): #RHOAS <a href="#HOAS">here</a>
-
-%!postproc(tex): #Lidentifiers "label{identifiers}"
-%!postproc(tex): #Ridentifiers "sref{identifiers}"
-%!postproc(html): #Lidentifiers <a name="identifiers"></a>
-%!postproc(html): #Ridentifiers <a href="#identifiers">here</a>
-
-%!postproc(tex): #Ljudgementforms "label{judgementforms}"
-%!postproc(tex): #Rjudgementforms "sref{judgementforms}"
-%!postproc(html): #Ljudgementforms <a name="judgementforms"></a>
-%!postproc(html): #Rjudgementforms <a href="#judgementforms">here</a>
-
-%!postproc(tex): #Llindefjudgements "label{lindefjudgements}"
-%!postproc(tex): #Rlindefjudgements "sref{lindefjudgements}"
-%!postproc(html): #Llindefjudgements <a name="lindefjudgements"></a>
-%!postproc(html): #Rlindefjudgements <a href="#lindefjudgements">here</a>
-
-%!postproc(tex): #Llinexpansion "label{linexpansion}"
-%!postproc(tex): #Rlinexpansion "sref{linexpansion}"
-%!postproc(html): #Llinexpansion <a name="linexpansion"></a>
-%!postproc(html): #Rlinexpansion <a href="#linexpansion">here</a>
-
-%!postproc(tex): #Loldgf "label{oldgf}"
-%!postproc(tex): #Roldgf "sref{oldgf}"
-%!postproc(html): #Loldgf <a name="oldgf"></a>
-%!postproc(html): #Roldgf <a href="#oldgf">here</a>
-
-%!postproc(tex): #Lopenabstract "label{openabstract}"
-%!postproc(tex): #Ropenabstract "sref{openabstract}"
-%!postproc(html): #Lopenabstract <a name="openabstract"></a>
-%!postproc(html): #Ropenabstract <a href="#openabstract">here</a>
-
-%!postproc(tex): #Loverloading "label{overloading}"
-%!postproc(tex): #Roverloading "sref{overloading}"
-%!postproc(html): #Loverloading <a name="overloading"></a>
-%!postproc(html): #Roverloading <a href="#overloading">here</a>
-
-%!postproc(tex): #Lparamjudgements "label{paramjudgements}"
-%!postproc(tex): #Rparamjudgements "sref{paramjudgements}"
-%!postproc(html): #Lparamjudgements <a name="paramjudgements"></a>
-%!postproc(html): #Rparamjudgements <a href="#paramjudgements">here</a>
-
-%!postproc(tex): #Lparamtypes "label{paramtypes}"
-%!postproc(tex): #Rparamtypes "sref{paramtypes}"
-%!postproc(html): #Lparamtypes <a name="paramtypes"></a>
-%!postproc(html): #Rparamtypes <a href="#paramtypes">here</a>
-
-%!postproc(tex): #Lparamvalues "label{paramvalues}"
-%!postproc(tex): #Rparamvalues "sref{paramvalues}"
-%!postproc(html): #Lparamvalues <a name="paramvalues"></a>
-%!postproc(html): #Rparamvalues <a href="#paramvalues">here</a>
-
-%!postproc(tex): #Lpredefabs "label{predefabs}"
-%!postproc(tex): #Rpredefabs "sref{predefabs}"
-%!postproc(html): #Lpredefabs <a name="predefabs"></a>
-%!postproc(html): #Rpredefabs <a href="#predefabs">here</a>
-
-%!postproc(tex): #Lpredefcnc "label{predefcnc}"
-%!postproc(tex): #Rpredefcnc "sref{predefcnc}"
-%!postproc(html): #Lpredefcnc <a name="predefcnc"></a>
-%!postproc(html): #Rpredefcnc <a href="#predefcnc">here</a>
-
-%!postproc(tex): #Lqualifiednames "label{qualifiednames}"
-%!postproc(tex): #Rqualifiednames "sref{qualifiednames}"
-%!postproc(html): #Lqualifiednames <a name="qualifiednames"></a>
-%!postproc(html): #Rqualifiednames <a href="#qualifiednames">here</a>
-
-%!postproc(tex): #Lrenaming "label{renaming}"
-%!postproc(tex): #Rrenaming "sref{renaming}"
-%!postproc(html): #Lrenaming <a name="renaming"></a>
-%!postproc(html): #Rrenaming <a href="#renaming">here</a>
-
-%!postproc(tex): #Lrestrictedinheritance "label{restrictedinheritance}"
-%!postproc(tex): #Rrestrictedinheritance "sref{restrictedinheritance}"
-%!postproc(html): #Lrestrictedinheritance <a name="restrictedinheritance"></a>
-%!postproc(html): #Rrestrictedinheritance <a href="#restrictedinheritance">here</a>
-
-%!postproc(tex): #Lreuse "label{reuse}"
-%!postproc(tex): #Rreuse "sref{reuse}"
-%!postproc(html): #Lreuse <a name="reuse"></a>
-%!postproc(html): #Rreuse <a href="#reuse">here</a>
-
-%!postproc(tex): #Lruntimevariables "label{runtimevariables}"
-%!postproc(tex): #Rruntimevariables "sref{runtimevariables}"
-%!postproc(html): #Lruntimevariables <a name="runtimevariables"></a>
-%!postproc(html): #Rruntimevariables <a href="#runtimevariables">here</a>
-
-%!postproc(tex): #Lstrtype "label{strtype}"
-%!postproc(tex): #Rstrtype "sref{strtype}"
-%!postproc(html): #Lstrtype <a name="strtype"></a>
-%!postproc(html): #Rstrtype <a href="#strtype">here</a>
-
-%!postproc(tex): #Lsubtyping "label{subtyping}"
-%!postproc(tex): #Rsubtyping "sref{subtyping}"
-%!postproc(html): #Lsubtyping <a name="subtyping"></a>
-%!postproc(html): #Rsubtyping <a href="#subtyping">here</a>
-
-%!postproc(tex): #Lsyntaxtrees "label{syntaxtrees}"
-%!postproc(tex): #Rsyntaxtrees "sref{syntaxtrees}"
-%!postproc(html): #Lsyntaxtrees <a name="syntaxtrees"></a>
-%!postproc(html): #Rsyntaxtrees <a href="#syntaxtrees">here</a>
-
-%!postproc(tex): #Ltables "label{tables}"
-%!postproc(tex): #Rtables "sref{tables}"
-%!postproc(html): #Ltables <a name="tables"></a>
-%!postproc(html): #Rtables <a href="#tables">here</a>
-
-%!postproc(tex): #Lvariablebinding "label{variablebinding}"
-%!postproc(tex): #Rvariablebinding "sref{variablebinding}"
-%!postproc(html): #Lvariablebinding <a name="variablebinding"></a>
-%!postproc(html): #Rvariablebinding <a href="#variablebinding">here</a>
-
-%% last, to avoid overriding with subsection* -> section
-%!postproc(tex): #PREFACE "subsection*{Preface}"
-%!postproc(tex): #OVERVIEW "subsection*{Overview}"
-%!postproc(html): #OVERVIEW <h2>Overview</h2>
-
-
-
-
-#NEW
-
-=Overview=
-
-This is a hands-on introduction to grammar writing in GF.
-
-Main ingredients of GF:
-- linguistics
-- functional programming
-
-
-Prerequisites:
-- some previous experience from some programming language
-- the basics of using computers, e.g. the use of 
-  text editors and the management of files.
-- knowledge of Unix commands is useful but not necessary
-- knowledge of many natural languages may add fun to experience
-
-
-
-
-#NEW
-
-==Outline==
-
-#Rchaptwo: a multilingual "Hello World" grammar. English, Finnish, Italian.
-
-#Rchapthree: a larger grammar for the domain of food. English and Italian.
-
-#Rchapfour: parameters - morphology and agreement.
-
-#Rchapfive: using the resource grammar library.
-
-#Rchapsix: semantics -  **dependent types**, **variable bindings**, 
-and **semantic definitions**.
-
-#Rchapseven: implementing formal languages.
-
-#Rchapeight: embedded grammar applications.
-
-
-
-#NEW
-
-==Slides==
-
-You can chop this tutorial into a set of slides by the command
-```
-  htmls gf-tutorial.html
-```
-where the program ``htmls`` is distributed with GF (see below), in
-
-  [``GF/src/tools/Htmls.hs`` http://digitalgrammars.com/gf/src/tools/Htmls.hs]
-
-The slides will appear as a set of files beginning with ``01-gf-tutorial.htmls``.
-
-Internal links will not work in the slide format, except for those in the
-upper left corner of each slide, and the links behind the "Contents" link.
-
-
-
-#NEW
-
-=Lesson 1: Getting Started with GF=
-
-
-#Lchaptwo
-
-Goals:
-- install and run GF
-- write the first GF grammar: a "Hello World" grammar in three languages
-- use GF for translation and multilingual generation
-
-
-#NEW
-
-==What GF is==
-
-We use the term GF for three different things:
-- a **system** (computer program) used for working with grammars
-- a **programming language** in which grammars can be written
-- a **theory** about grammars and languages
-
-
-The GF system is an implementation
-of the GF programming language, which in turn is built on the ideas of the
-GF theory. 
-
-The focus of this tutorial is on using the GF programming language.
-
-At the same time, we learn the way of thinking in the GF theory. 
-
-We make the grammars run on a computer by 
-using the GF system. 
-
-
-#NEW
-
-==GF grammars and language processing tasks==
-
-A GF program is called a **grammar**. 
-
-A grammar defines a language. 
-
-From this definition, language processing components can be derived:
-- **parsing**: to analyse the language
-- **linearization**: to generate the language
-- **translation**: to analyse one language and generate another
-
-
-In general, a GF grammar is **multilingual**:
-- many languages in one grammar
-- translations between them
-
-
-
-
-
-
-
-#NEW
-
-==Getting the GF system==
-
-Open-source free software, downloaded via the GF Homepage:
-
-[``digitalgrammars.com/gf`` http://digitalgrammars.com/gf/]
-
-There you find
-- binaries for Linux, Mac OS X, and Windows
-- source code and documentation
-- grammar libraries and examples 
-
-
-Many examples in this tutorial are
-[online http://digitalgrammars.com/gf/examples/tutorial].
-
-Normally you don't have to compile GF yourself.
-But, if you do want to compile GF from source follow the
-instructions in the [Developers Guide gf-developers.html].
-
-
-#NEW
-
-==Running the GF system==
-
-Type ``gf`` in the Unix (or Cygwin) shell:
-```
-  % gf
-```
-You will see GF's welcome message and the prompt ``>``.
-The command
-```
-  > help
-```
-will give you a list of available commands.
-
-As a common convention, we will use
-- ``%`` as a prompt that marks system commands
-- ``>`` as a prompt that marks GF commands
-
-
-Thus you should not type these prompts, but only the characters that
-follow them.
-
-
-#NEW
-
-==A "Hello World" grammar==
-
-Like most programming language tutorials, we start with a
-program that prints "Hello World" on the terminal. 
-
-Extra features:
-- **Multilinguality**: the message is printed in many languages.
-- **Reversibility**: in addition to printing, you can **parse** the
-  message and **translate** it to other languages.
-
-
-#NEW
-
-===The program: abstract syntax and concrete syntaxes===
-
-A GF program, in general, is a **multilingual grammar**. Its main parts
-are
-- an **abstract syntax**
-- one or more **concrete syntaxes**
-
-
-The abstract syntax defines what **meanings**
-can be expressed in the grammar
-- //Greetings//, where we greet a //Recipient//, which can be 
-  //World// or //Mum// or //Friends// 
-
-
-
-#NEW
-
-GF code for the abstract syntax:
-```
-  -- a "Hello World" grammar
-  abstract Hello = {
-
-    flags startcat = Greeting ;
-
-    cat Greeting ; Recipient ;
-
-    fun 
-      Hello : Recipient -> Greeting ;
-      World, Mum, Friends : Recipient ;
-  }
-```
-The code has the following parts:
-- a **comment** (optional), saying what the module is doing 
-- a **module header** indicating that it is an abstract syntax
-  module named ``Hello``
-- a **module body** in braces, consisting of
-  - a **startcat flag declaration** stating that ``Greeting`` is the
-    default start category for parsing and generation
-  - **category declarations** introducing two categories, i.e. types of meanings
-  - **function declarations** introducing three meaning-building functions
-
-
-#NEW
-
-English concrete syntax (mapping from meanings to strings):
-```
-  concrete HelloEng of Hello = {
-
-    lincat Greeting, Recipient = {s : Str} ;
-
-    lin 
-      Hello recip = {s = "hello" ++ recip.s} ;
-      World = {s = "world"} ;
-      Mum = {s = "mum"} ;
-      Friends = {s = "friends"} ;
-  }
-```
-The major parts of this code are:
-- a module header indicating that it is a concrete syntax of the abstract syntax
-  ``Hello``, itself named ``HelloEng``
-- a module body in curly brackets, consisting of
-  - **linearization type definitions** stating that 
-    ``Greeting`` and ``Recipient`` are **records** with a **string** ``s``
-  - **linearization definitions** telling what records are assigned to
-    each of the meanings defined in the abstract syntax
-
-
-Notice the concatenation ``++`` and the record projection ``.``.
-
-
-#NEW
-
-Finnish and an Italian concrete syntaxes:
-```
-  concrete HelloFin of Hello = {
-    lincat Greeting, Recipient = {s : Str} ;
-    lin 
-      Hello recip = {s = "terve" ++ recip.s} ;
-      World = {s = "maailma"} ;
-      Mum = {s = "äiti"} ;
-      Friends = {s = "ystävät"} ;
-  }
-
-  concrete HelloIta of Hello = {
-    lincat Greeting, Recipient = {s : Str} ;
-    lin 
-      Hello recip = {s = "ciao" ++ recip.s} ;
-      World = {s = "mondo"} ;
-      Mum = {s = "mamma"} ;
-      Friends = {s = "amici"} ;
-  }
-```
-
-
-#NEW
-
-===Using grammars in the GF system===
-
-In order to compile the grammar in GF,
-we create four files, one for each module, named //Modulename//``.gf``:
-```
-  Hello.gf  HelloEng.gf  HelloFin.gf  HelloIta.gf
-```
-The first GF command: **import** a grammar.
-```
-  > import HelloEng.gf
-```
-All commands also have short names; here:
-```
-  > i HelloEng.gf
-```
-The GF system will **compile** your grammar 
-into an internal representation and show the CPU time was consumed, followed
-by a new prompt:
-```
-  > i HelloEng.gf
-  - compiling Hello.gf...   wrote file Hello.gfo 8 msec
-  - compiling HelloEng.gf...   wrote file HelloEng.gfo 12 msec
-
-  12 msec
-  >
-```
-
-#NEW
-
-You can use GF for **parsing** (``parse`` = ``p``)
-```
-  > parse "hello world"
-  Hello World
-```
-Parsing takes a **string** into an **abstract syntax tree**.
-
-The notation for trees is that of **function application**:
-```
-  function argument1 ... argumentn
-```
-Parentheses are only needed for grouping. 
-
-Parsing something that is not in grammar will fail:
-```
-  > parse "hello dad"
-  Unknown words: dad
-
-  > parse "world hello"
-  no tree found
-```
-
-#NEW
-
-You can also use GF for **linearization** (``linearize = l``). 
-It takes trees into strings:
-```
-  > linearize Hello World
-  hello world
-```
-**Translation**: **pipe** linearization to parsing:
-```
-  > import HelloEng.gf
-  > import HelloIta.gf
-
-  > parse -lang=HelloEng "hello mum" | linearize -lang=HelloIta
-  ciao mamma
-```
-Default of the language flag (``-lang``): the last-imported concrete syntax.
-
-**Multilingual generation**:
-```
-  > parse -lang=HelloEng "hello friends" | linearize
-  terve ystävät
-  ciao amici
-  hello friends
-```
-Linearization is by default to all available languages.
-
-#NEW
-
-===Exercises on the Hello World grammar===
-
-+ Test the parsing and translation examples shown above, as well as
-some other examples, in different combinations of languages.
-
-+ Extend the grammar ``Hello.gf`` and some of the
-concrete syntaxes by five new recipients and one new greeting
-form.
-
-+ Add a concrete syntax for some other
-languages you might know.
-
-+ Add a pair of greetings that are expressed in one and 
-the same way in
-one language and in two different ways in another. 
-For instance, //good morning//
-and //good afternoon// in English are both expressed 
-as //buongiorno// in Italian.
-Test what happens when you translate //buongiorno// to English in GF.
-
-+ Inject errors in the ``Hello`` grammars, for example, leave out
-some line, omit a variable in a ``lin`` rule, or change the name 
-in one occurrence
-of a variable. Inspect the error messages generated by GF.
-
-
-#NEW
-
-==Using grammars from outside GF==
-
-You can use the ``gf`` program in a Unix pipe. 
-- echo a GF command
-- pipe it into GF with grammar names as arguments
-
-
-```
-  % echo "l Hello World" | gf HelloEng.gf HelloFin.gf HelloIta.gf
-```
-You can also write a **script**, a file containing the lines
-```
-  import HelloEng.gf
-  import HelloFin.gf
-  import HelloIta.gf
-  linearize Hello World
-```
-
-
-#NEW
-
-==GF scripts==
-
-If we name this script ``hello.gfs``, we can do
-```
-  $ gf --run <hello.gfs
-
-  ciao mondo
-  terve maailma
-  hello world
-```
-The option ``--run`` removes prompts, CPU time, and other messages. 
-
-See #Rchapeight, for stand-alone programs that don't need the GF system to run.
-
-**Exercise**. (For Unix hackers.) Write a GF application that reads
-an English string from the standard input and writes an Italian
-translation to the output.
-
-
-#NEW
-
-==What else can be done with the grammar==
-
-Some more functions that will be covered:
-- **morphological analysis**: find out the possible inflection forms of words
-- **morphological synthesis**: generate all inflection forms of words
-- **random generation**: generate random expressions
-- **corpus generation**: generate all expressions
-- **treebank generation**: generate a list of trees with their linearizations
-- **teaching quizzes**: train morphology and translation
-- **multilingual authoring**: create a document in many languages simultaneously
-- **speech input**: optimize a speech recognition system for a grammar
-
-
-
-#NEW
-
-==Embedded grammar applications==
-
-Application programs, using techniques from #Rchapeight:
-- compile grammars to new formats, such as speech recognition grammars
-- embed grammars in Java and Haskell programs
-- build applications using compilation and embedding:
-  - voice commands
-  - spoken language translators
-  - dialogue systems
-  - user interfaces
-  - localization: render the messages printed by a program
-    in different languages
-
-
-
-
-#NEW
-
-=Lesson 2: Designing a grammar for complex phrases=
-
-#Lchapthree
-
-Goals:
-- build a larger grammar: phrases about food in English and Italian
-- learn to write reusable library functions ("operations")
-- learn the basics of GF's module system
-
-
-#NEW
-
-
-==The abstract syntax Food==
-
-Phrases usable for speaking about food:
-- the start category is ``Phrase``
-- a ``Phrase`` can be built by assigning a ``Quality`` to an ``Item`` 
-  (e.g. //this cheese is Italian//)
-- an``Item`` is build from a ``Kind`` by prefixing //this// or //that// 
-  (e.g. //this wine//)
-- a ``Kind`` is either **atomic** (e.g. //cheese//), or formed 
-  qualifying a given ``Kind`` with a ``Quality`` (e.g. //Italian cheese//)
-- a ``Quality`` is either atomic (e.g. //Italian//,
-  or built by modifying a given ``Quality`` with the word //very// (e.g. //very warm//)
-
-
-Abstract syntax:
-```
-  abstract Food = {
-
-    flags startcat = Phrase ;
-
-    cat
-      Phrase ; Item ; Kind ; Quality ;
-
-    fun
-      Is : Item -> Quality -> Phrase ;
-      This, That : Kind -> Item ;
-      QKind : Quality -> Kind -> Kind ;
-      Wine, Cheese, Fish : Kind ;
-      Very : Quality -> Quality ;
-      Fresh, Warm, Italian, Expensive, Delicious, Boring : Quality ;
-  }
-```
-Example ``Phrase``
-```
-  Is (This (QKind Delicious (QKind Italian Wine))) (Very (Very Expensive))
-  this delicious Italian wine is very very expensive
-```
-
-
-#NEW
-
-==The concrete syntax FoodEng==
-
-```
-  concrete FoodEng of Food = {
-
-    lincat
-      Phrase, Item, Kind, Quality = {s : Str} ;
-
-    lin
-      Is item quality = {s = item.s ++ "is" ++ quality.s} ;
-      This kind = {s = "this" ++ kind.s} ;
-      That kind = {s = "that" ++ kind.s} ;
-      QKind quality kind = {s = quality.s ++ kind.s} ;
-      Wine = {s = "wine"} ;
-      Cheese = {s = "cheese"} ;
-      Fish = {s = "fish"} ;
-      Very quality = {s = "very" ++ quality.s} ;
-      Fresh = {s = "fresh"} ;
-      Warm = {s = "warm"} ;
-      Italian = {s = "Italian"} ;
-      Expensive = {s = "expensive"} ;
-      Delicious = {s = "delicious"} ;
-      Boring = {s = "boring"} ;
-  }  
-```
-
-#NEW
-
-Test the grammar for parsing:
-```
-  > import FoodEng.gf
-  > parse "this delicious wine is very very Italian"
-  Is (This (QKind Delicious Wine)) (Very (Very Italian))
-```
-Parse in other categories setting the ``cat`` flag:
-```
-  p -cat=Kind "very Italian wine"
-  QKind (Very Italian) Wine
-```
-
-
-#NEW
-
-===Exercises on the Food grammar===
-
-+ Extend the ``Food`` grammar by ten new food kinds and
-qualities, and run the parser with new kinds of examples.
-
-+ Add a rule that enables question phrases of the form 
-//is this cheese Italian//.
-
-+ Enable the optional prefixing of 
-phrases with the words "excuse me but". Do this in such a way that
-the prefix can occur at most once.
-
-
-
-#NEW
-
-==Commands for testing grammars==
-
-===Generating trees and strings===
-
-Random generation (``generate_random = gr``): build
-build a random tree in accordance with an abstract syntax:
-```
-  > generate_random
-  Is (This (QKind Italian Fish)) Fresh
-```
-By using a pipe, random generation can be fed into linearization:
-```
-  > generate_random | linearize
-  this Italian fish is fresh
-```
-Use the ``number`` flag to generate several trees:
-```
-  > gr -number=4 | l
-  that wine is boring
-  that fresh cheese is fresh
-  that cheese is very boring
-  this cheese is Italian
-```
-
-#NEW
-
-To generate //all// phrases that a grammar can produce,
-use ``generate_trees = gt``.
-```
-  > generate_trees | l
-  that cheese is very Italian
-  that cheese is very boring
-  that cheese is very delicious
-  ...
-  this wine is fresh
-  this wine is warm
-```
-The default **depth** is 3; the depth can be
-set by using the ``depth`` flag:
-```
-  > generate_trees -depth=2 | l
-```
-What options a command has can be seen by the ``help = h`` command:
-```
-  > help gr
-  > help gt
-```
-
-
-#NEW
-
-===Exercises on generation===
-
-+ If the command ``gt`` generated all
-trees in your grammar, it would never terminate. Why?
-
-+ Measure how many trees the grammar gives with depths 4 and 5,
-respectively. **Hint**. You can 
-use the Unix **word count** command ``wc`` to count lines.
-
-
-
-#NEW
-
-===More on pipes: tracing===
-
-Put the **tracing** option ``-tr`` to each command whose output you
-want to see:
-```
-  > gr -tr | l -tr | p
-
-  Is (This Cheese) Boring
-  this cheese is boring
-  Is (This Cheese) Boring  
-```
-Useful for test purposes: the pipe above can show
-if a grammar is **ambiguous**, i.e.
-contains strings that can be parsed in more than one way.
-
-**Exercise**. Extend the ``Food`` grammar so that it produces ambiguous 
-strings, and try out the ambiguity test.
-
-
-#NEW
-
-===Writing and reading files===
-
-To save the outputs into a file, pipe it to the ``write_file = wf`` command,
-```
-  > gr -number=10 | linearize | write_file -file=exx.tmp
-```
-To read a file to GF, use the ``read_file = rf`` command,
-```
-  > read_file -file=exx.tmp -lines | parse
-```
-The flag ``-lines`` tells GF to read each line of the file separately. 
-
-Files with examples can be used for **regression testing**
-of grammars - the most systematic way to do this is by
-**treebanks**; see #Rsectreebank.
-
-
-#NEW
-
-===Visualizing trees===
-
-Parentheses give a linear representation of trees,
-useful for the computer. 
-
-Human eye may prefer to see a visualization: ``visualize_tree = vt``:
-``` 
-  > parse "this delicious cheese is very Italian" | visualize_tree
-```
-The tree is generated in postscript (``.ps``) file. The ``-view`` option is used for
-telling what command to use to view the file. Its default is ``"gv"``, which works
-on most Linux installations. On a Mac, one would probably write
-``` 
-  > parse "this delicious cheese is very Italian" | visualize_tree -view="open"
-```
-
-
-
-#MYTREE
-
-This command uses the program [Graphviz http://www.graphviz.org/], which you
-might not have, but which are freely available on the web.
-
-You can save the temporary file ``_grph.dot``, 
-which the command ``vt`` produces. 
-
-Then you can process this file with the ``dot`` 
-program (from the Graphviz package).
-```
-  % dot -Tpng _grph.dot > mytree.png
-```
-
-
-#NEW
-
-===System commands===
-
-You can give a **system command** without leaving GF:
-``!`` followed by a Unix command,
-```
-  > ! dot -Tpng grphtmp.dot > mytree.png
-  > ! open mytree.png
-```
-A system command may also receive its argument from
-a GF pipes. It then has the name ``sp`` = ``system_pipe``:
-```
-  > generate_trees -depth=4 | sp -command="wc -l"
-```
-This command example returns the number of generated trees.
-
-
-**Exercise**.
-Measure how many trees the grammar ``FoodEng`` gives with depths 4 and 5,
-respectively. Use the Unix **word count** command ``wc`` to count lines, and
-a system pipe from a GF command into a Unix command.
-
-
-
-
-
-#NEW
-
-==An Italian concrete syntax==
-
-#Lsecanitalian
-
-Just (?) replace English words with their dictionary equivalents:
-```
-  concrete FoodIta of Food = {
-
-    lincat
-      Phrase, Item, Kind, Quality = {s : Str} ;
-
-    lin
-      Is item quality = {s = item.s ++ "è" ++ quality.s} ;
-      This kind = {s = "questo" ++ kind.s} ;
-      That kind = {s = "quel" ++ kind.s} ;
-      QKind quality kind = {s = kind.s ++ quality.s} ;
-      Wine = {s = "vino"} ;
-      Cheese = {s = "formaggio"} ;
-      Fish = {s = "pesce"} ;
-      Very quality = {s = "molto" ++ quality.s} ;
-      Fresh = {s = "fresco"} ;
-      Warm = {s = "caldo"} ;
-      Italian = {s = "italiano"} ;
-      Expensive = {s = "caro"} ;
-      Delicious = {s = "delizioso"} ;
-      Boring = {s = "noioso"} ;
-  }
-```
-
-
-#NEW
-
-Not just replacing words:
-
-The order of a quality and the kind it modifies is changed in
-```
-    QKind quality kind = {s = kind.s ++ quality.s} ;
-```
-Thus Italian says ``vino italiano`` for ``Italian wine``. 
-
-(Some Italian adjectives
-are put before the noun. This distinction can be controlled by parameters, 
-which are introduced in #Rchapfour.)
-
-#NEW
-
-===Exercises on multilinguality===
-
-+ Write a concrete syntax of ``Food`` for some other language.
-You will probably end up with grammatically incorrect 
-linearizations - but don't
-worry about this yet.
-
-+ If you have written ``Food`` for German, Swedish, or some
-other language, test with random or exhaustive generation what constructs
-come out incorrect, and prepare a list of those ones that cannot be helped
-with the currently available fragment of GF. You can return to your list
-after having worked out #Rchapfour.
-
-
-
-
-#NEW
-
-==Free variation==
-
-Semantically indistinguishable ways of expressing a thing.
-
-The **variants** construct of GF expresses free variation. For example,
-```
-  lin Delicious = {s = "delicious" | "exquisit" | "tasty"} ;
-```
-By default, the ``linearize`` command
-shows only the first variant from such lists; to see them
-all, use the option ``-all``:
-```
-  > p "this exquisit wine is delicious" | l -all
-  this delicious wine is delicious
-  this delicious wine is exquisit
-  ...
-```
-
-#NEW
-
-An equivalent notation for variants is
-```
-  lin Delicious = {s = variants {"delicious" ; "exquisit" ; "tasty"}} ;
-```
-This notation also allows the limiting case: an empty variant list,
-```
-  variants {}
-```
-It can be used e.g. if a word lacks a certain inflection form. 
-
-Free variation works for all types in concrete syntax; all terms in
-a variant list must be of the same type.
-
-
-#NEW
-
-==More application of multilingual grammars==
-
-===Multilingual treebanks===
-
-#Lsectreebank
-
-**Multilingual treebank**: a set of trees with their
-linearizations in different languages:
-```
-  > gr -number=2 | l -treebank
-
-  Is (That Cheese) (Very Boring)
-  quel formaggio è molto noioso
-  that cheese is very boring
-
-  Is (That Cheese) Fresh
-  quel formaggio è fresco
-  that cheese is fresh
-```
-
-
-
-#NEW
-
-===Translation quiz===
-
-``translation_quiz = tq``:
-generate random sentences, display them in one language, and check the user's
-answer given in another language. 
-```
-  > translation_quiz -from=FoodEng -to=FoodIta
-
-  Welcome to GF Translation Quiz.
-  The quiz is over when you have done at least 10 examples
-  with at least 75 % success.
-  You can interrupt the quiz by entering a line consisting of a dot ('.').
-
-  this fish is warm
-  questo pesce è caldo
-  > Yes.
-  Score 1/1
-
-  this cheese is Italian
-  questo formaggio è noioso
-  > No, not questo formaggio è noioso, but
-  questo formaggio è italiano
-
-  Score 1/2
-  this fish is expensive
-```
-
-
-
-#NEW
-
-==Context-free grammars and GF==
-
-===The "cf" grammar format===
-
-The grammar ``FoodEng`` can be written in a BNF format as follows:
-```
-  Is.        Phrase  ::= Item "is" Quality ;
-  That.      Item    ::= "that" Kind ;
-  This.      Item    ::= "this" Kind ;
-  QKind.     Kind    ::= Quality Kind ;
-  Cheese.    Kind    ::= "cheese" ;
-  Fish.      Kind    ::= "fish" ;
-  Wine.      Kind    ::= "wine" ;
-  Italian.   Quality ::= "Italian" ;
-  Boring.    Quality ::= "boring" ;
-  Delicious. Quality ::= "delicious" ;
-  Expensive. Quality ::= "expensive" ;
-  Fresh.     Quality ::= "fresh" ;
-  Very.      Quality ::= "very" Quality ;
-  Warm.      Quality ::= "warm" ;
-```
-GF can convert BNF grammars into GF. 
-BNF files are recognized by the file name suffix ``.cf`` (for **context-free**): 
-```
-  > import food.cf
-```
-The compiler creates separate abstract and concrete modules internally.
-
-
-#NEW
-
-===Restrictions of context-free grammars===
-
-Separating concrete and abstract syntax allows
-three deviations from context-free grammar:
-- **permutation**: changing the order of constituents
-- **suppression**: omitting constituents
-- **reduplication**: repeating constituents
-
-
-**Exercise**. Define the non-context-free
-copy language ``{x x | x <- (a|b)*}`` in GF.
-
-
-
-#NEW
-
-%--!
-==Modules and files==
-
-GF uses suffixes to recognize different file formats:
-- Source files: //Modulename//``.gf``
-- Target files: //Modulename//``.gfo``
-
-
-Importing generates target from source:
-```
-  > i FoodEng.gf
-  - compiling Food.gf...   wrote file Food.gfo 16 msec
-  - compiling FoodEng.gf...   wrote file FoodEng.gfo 20 msec
-```
-The ``.gfo`` format (="GF Object") is precompiled GF, which is
-faster to load than source GF (``.gf``).
-
-When reading a module, GF decides whether
-to use an existing ``.gfo`` file or to generate
-a new one, by looking at modification times.
-
-
-#NEW
-
-**Exercise**.  What happens when you import ``FoodEng.gf`` for 
-a second time? Try this in different situations:
-- Right after importing it the first time (the modules are kept in
-  the memory of GF and need no reloading).
-- After issuing the command ``empty`` (``e``), which clears the memory
-  of GF.
-- After making a small change in ``FoodEng.gf``, be it only an added space.
-- After making a change in ``Food.gf``.
-
-
-
-#NEW
-
-==Using operations and resource modules==
-
-===Operation definitions===
-
-The golden rule of functional programmin:
-
-//Whenever you find yourself programming by copy-and-paste, write a function instead.//
-
-Functions in concrete syntax are defined using the keyword ``oper`` (for
-**operation**), distinct from ``fun`` for the sake of clarity.
-
-Example:
-```
-  oper ss : Str -> {s : Str} = \x -> {s = x} ;
-```
-The operation can be **applied** to an argument, and GF will
-**compute** the value:
-```
-  ss "boy" ===> {s = "boy"}
-```
-The symbol ``===>`` will be used for computation.
-
-
-#NEW
-
-Notice the **lambda abstraction** form 
-- ``\``//x// ``->`` //t//
-
-
-This is read:
-- function with variable //x// and **function body** //t//
-
-
-For lambda abstraction with multiple arguments, we have the shorthand
-```
-  \x,y -> t   ===  \x -> \y -> t
-```
-Linearization rules actually use syntactic
-sugar for abstraction:
-```
-  lin f x = t   ===  lin f = \x -> t
-```
-
-
-
-#NEW
-
-%--!
-===The ``resource`` module type===
-
-The ``resource`` module type is used to package
-``oper`` definitions into reusable resources. 
-```
-  resource StringOper = {
-    oper
-      SS : Type = {s : Str} ;
-      ss : Str -> SS = \x -> {s = x} ;
-      cc : SS -> SS -> SS = \x,y -> ss (x.s ++ y.s) ;
-      prefix : Str -> SS -> SS = \p,x -> ss (p ++ x.s) ;
-  }
-```
-
-
-#NEW
-
-%--!
-===Opening a resource===
-
-Any number of ``resource`` modules can be
-**open**ed in a ``concrete`` syntax.
-```
-  concrete FoodEng of Food = open StringOper in {
-
-    lincat
-      S, Item, Kind, Quality = SS ;
-
-    lin
-      Is item quality = cc item (prefix "is" quality) ;
-      This k = prefix "this" k ;
-      That k = prefix "that" k ;
-      QKind k q = cc k q ;
-      Wine = ss "wine" ;
-      Cheese = ss "cheese" ;
-      Fish = ss "fish" ;
-      Very = prefix "very" ;
-      Fresh = ss "fresh" ;
-      Warm = ss "warm" ;
-      Italian = ss "Italian" ;
-      Expensive = ss "expensive" ;
-      Delicious = ss "delicious" ;
-      Boring = ss "boring" ;
-  }
-```
-
-
-#NEW
-
-%--!
-===Partial application===
-
-#Lsecpartapp
-
-The rule
-```
-  lin This k = prefix "this" k ;
-```
-can be written more concisely
-```
-  lin This = prefix "this" ;
-```
-Part of the art in functional programming: 
-decide the order of arguments in a function, 
-so that partial application can be used as much as possible. 
-
-For instance, ``prefix`` is typically applied to 
-linearization variables with constant strings. Hence we
-put the ``Str`` argument before the ``SS`` argument.
-
-
-**Exercise**. Define an operation ``infix`` analogous to ``prefix``,
-such that it allows you to write
-```
-  lin Is = infix "is" ;
-```
-
-
-#NEW
-
-===Testing resource modules===
-
-Import with the flag ``-retain``, 
-```
-  > import -retain StringOper.gf
-```
-Compute the value with ``compute_concrete = cc``,
-```
-  > compute_concrete prefix "in" (ss "addition")
-  {s : Str = "in" ++ "addition"}
-```
-
-
-#NEW
-
-==Grammar architecture==
-
-#Lsecarchitecture
-
-===Extending a grammar===
-
-A new module can **extend** an old one:
-```
-  abstract Morefood = Food ** {
-    cat
-      Question ;
-    fun
-      QIs : Item -> Quality -> Question ;
-      Pizza : Kind ;      
-  }
-```
-Parallel to the abstract syntax, extensions can
-be built for concrete syntaxes:
-```
-  concrete MorefoodEng of Morefood = FoodEng ** {
-    lincat
-      Question = {s : Str} ;
-    lin
-      QIs item quality = {s = "is" ++ item.s ++ quality.s} ;
-      Pizza = {s = "pizza"} ;
-  }
-```
-The effect of extension: all of the contents of the extended
-and extending modules are put together. 
-
-In other words: the new module **inherits** the contents of the old module.
-
-#NEW
-
-Simultaneous extension and opening:
-```
-  concrete MorefoodIta of Morefood = FoodIta ** open StringOper in {
-    lincat
-      Question = SS ;
-    lin
-      QIs item quality = ss (item.s ++ "è" ++ quality.s) ;
-      Pizza = ss "pizza" ;
-  }
-```
-Resource modules can extend other resource modules - thus it is 
-possible to build resource hierarchies.
-
-
-
-#NEW
-
-===Multiple inheritance===
-
-Extend several grammars at the same time:
-```
-  abstract Foodmarket = Food, Fruit, Mushroom ** {
-    fun 
-      FruitKind    : Fruit    -> Kind ;
-      MushroomKind : Mushroom -> Kind ;
-    }
-```
-where
-```
-  abstract Fruit = {
-    cat Fruit ;
-    fun Apple, Peach : Fruit ;
-  }
-
-  abstract Mushroom = {
-    cat Mushroom ;
-    fun Cep, Agaric : Mushroom ;
-  }
-```
-
-**Exercise**. Refactor ``Food`` by taking apart ``Wine`` into a special
-``Drink`` module.
-
-
-
-#NEW
-
-=Lesson 3: Grammars with parameters=
-
-#Lchapfour
-
-Goals:
-- implement sophisticated linguistic structures:
-  - morphology: the inflection of words
-  - agreement: rules for selecting word forms in syntactic combinations
-
-
-- Cover all GF constructs for concrete syntax
-
-
-It is possible to skip this chapter and go directly
-to the next, since the use of the GF Resource Grammar library
-makes it unnecessary to use parameters: they 
-could be left to library implementors.
-
-
-#NEW
-
-==The problem: words have to be inflected==
-
-Plural forms are needed in things like
-#BEQU
-//these Italian wines are delicious//
-#ENQU
-This requires two things:
-- the **inflection** of nouns and verbs in singular and plural
-- the **agreement** of the verb to subject: 
-  the verb must have the same number as the subject
-
-
-Different languages have different types of inflection and agreement.
-- Italian has also gender (masculine vs. feminine).
-
-
-
-In a multilingual grammar,
-we want to ignore such distinctions in abstract syntax.
-
-**Exercise**. Make a list of the possible forms that nouns,
-adjectives, and verbs can have in some languages that you know.
-
-
-#NEW
-
-==Parameters and tables==
-
-We define the **parameter type** of number in English by
-a new form of judgement:
-```
-  param Number = Sg | Pl ;
-```
-This judgement defines the parameter type ``Number`` by listing
-its two **constructors**, ``Sg`` and ``Pl`` 
-(singular and plural). 
-
-We give ``Kind`` a linearization type that has a **table** depending on number:
-```
-  lincat Kind = {s : Number => Str} ;
-```
-The **table type** ``Number => Str`` is similar a function type 
-(``Number -> Str``). 
-
-Difference: the argument must be a parameter type. Then
-the argument-value pairs can be listed in a finite table. 
-
-#NEW
-
-Here is a table:
-```
-  lin Cheese = {
-    s = table {
-      Sg => "cheese" ;
-      Pl => "cheeses"
-    }
-  } ;
-```
-The table has **branches**, with a **pattern** on the
-left of the arrow ``=>`` and a **value** on the right.
-
-The application of a table is done by the **selection** operator ``!``. 
-
-It which is computed by **pattern matching**: return
-the value from the first branch whose pattern matches the
-argument. For instance,
-```
-   table {Sg => "cheese" ; Pl => "cheeses"} ! Pl 
-   ===> "cheeses"
-```
-
-#NEW
-
-**Case expressions** are syntactic sugar:
-```
-  case e of {...} ===  table {...} ! e
-```
-Since they are familiar to Haskell and ML programmers, they can come out handy
-when writing GF programs.
-
-
-#NEW
-
-Constructors can take arguments from other parameter types. 
-
-Example: forms of English verbs (except //be//):
-```
-  param VerbForm = VPresent Number | VPast | VPastPart | VPresPart ;
-```
-Fact expressed: only present tense has number variation. 
-
-Example table: the forms of the verb //drink//:
-```
-  table {
-    VPresent Sg => "drinks" ;
-    VPresent Pl => "drink" ;
-    VPast       => "drank" ;
-    VPastPart   => "drunk" ;
-    VPresPart   => "drinking"
-    }
-``` 
-
-
-**Exercise**. In an earlier exercise (previous section), 
-you made a list of the possible 
-forms that nouns, adjectives, and verbs can have in some languages that 
-you know. Now take some of the results and implement them by
-using parameter type definitions and tables. Write them into a ``resource``
-module, which you can test by using the command ``compute_concrete``.
-
-
-
-#NEW
-
-==Inflection tables and paradigms==
-
-A morphological **paradigm** is a formula telling how a class of 
-words is inflected.
-
-From the GF point of view, a paradigm is a function that takes 
-a **lemma** (also known as a **dictionary form**, or a **citation form**) and 
-returns an inflection table. 
-
-The following operation defines the regular noun paradigm of English:
-```
-  oper regNoun : Str -> {s : Number => Str} = \dog -> {
-    s = table {
-      Sg => dog ;
-      Pl => dog + "s"
-      }
-    } ;
-```
-The **gluing** operator ``+`` glues strings to one **token**:
-```
-  (regNoun "cheese").s ! Pl  ===> "cheese" + "s"  ===>  "cheeses"
-```
-
-
-#NEW
-
-A more complex example: regular verbs,
-```
-  oper regVerb : Str -> {s : VerbForm => Str} = \talk -> {
-    s = table {
-      VPresent Sg => talk + "s" ;
-      VPresent Pl => talk ;
-      VPresPart   => talk + "ing" ;
-      _           => talk + "ed"
-      }
-    } ;
-```
-The catch-all case for the past tense and the past participle
-uses a **wild card** pattern ``_``. 
-
-
-#NEW
-
-===Exercises on morphology===
-
-+ Identify cases in which the ``regNoun`` paradigm does not
-apply in English, and implement some alternative paradigms.
-
-+ Implement some regular paradigms for other languages you have
-considered in earlier exercises.
-
-
-
-#NEW
-
-==Using parameters in concrete syntax==
-
-Purpose: a more radical
-variation between languages
-than just the use of different words and word orders. 
-
-We add to the grammar ``Food`` two rules for forming plural items:
-```
-  fun These, Those : Kind -> Item ;
-```
-We also add a noun which in Italian has the feminine case:
-```
-  fun Pizza : Kind ;
-```
-This will force us to deal with gender- 
-
-
-#NEW
-
-%--!
-===Agreement===
-
-In English, the phrase-forming rule
-```
-  fun Is : Item -> Quality -> Phrase ;
-```
-is affected by the number because of **subject-verb agreement**:
-the verb of a sentence must be inflected in the number of the subject,
-```
-  Is (This Pizza) Warm   ===>  "this pizza is warm"
-  Is (These Pizza) Warm  ===>  "these pizzas are warm"
-```
-It is the **copula** (the verb //be//) that is affected:
-```
-  oper copula : Number -> Str = \n -> 
-    case n of {
-      Sg => "is" ;
-      Pl => "are"
-      } ;
-```
-The **subject** ``Item`` must have such a number to provide to the copula:
-```
-  lincat Item = {s : Str ; n : Number} ;
-```
-Now we can write
-```
-  lin Is item qual = {s = item.s ++ copula item.n ++ qual.s} ;
-```
-
-
-
-#NEW
-
-===Determiners===
-
-How does an ``Item`` subject receive its number? The rules
-```
-  fun This, These : Kind -> Item ;
-```
-add **determiners**, either //this// or //these//, which
-require different //this pizza// vs.
-//these pizzas//. 
-
-Thus ``Kind`` must have both singular and plural forms:
-```
-  lincat Kind = {s : Number => Str} ;
-```
-We can write
-```
-  lin This kind = {
-    s = "this" ++ kind.s ! Sg ; 
-    n = Sg
-  } ; 
-
-  lin These kind = {
-    s = "these" ++ kind.s ! Pl ; 
-    n = Pl
-  } ; 
-```
-
-
-#NEW
-
-To avoid copy-and-paste, we can factor out the pattern of determination,
-```
-  oper det : 
-    Str -> Number -> {s : Number => Str} -> {s : Str ; n : Number} = 
-      \det,n,kind -> {
-      s = det ++ kind.s ! n ; 
-      n = n
-    } ; 
-```
-Now we can write
-```
-  lin This  = det Sg "this" ;
-  lin These = det Pl "these" ;
-```
-In a more **lexicalized** grammar, determiners would be a category:
-```
-  lincat Det = {s : Str ; n : Number} ;
-  fun Det : Det -> Kind -> Item ;
-  lin Det det kind = {
-      s = det.s ++ kind.s ! det.n ; 
-      n = det.n
-    } ; 
-```
-
-
-#NEW
-
-===Parametric vs. inherent features===
-
-``Kind``s have number as a **parametric feature**: both singular and plural
-can be formed,
-```
-  lincat Kind = {s : Number => Str} ;
-```
-``Item``s have number as an **inherent feature**: they are inherently either
-singular or plural,
-```
-  lincat Item = {s : Str ; n : Number} ;
-```
-Italian ``Kind`` will have parametric number and inherent gender:
-```
-  lincat Kind = {s : Number => Str ; g : Gender} ;
-```
-
-
-#NEW
-
-Questions to ask when designing parameters:
-- existence: what forms are possible to build by morphological and
-  other means?
-- need: what features are expected via agreement or government?
-
-
-Dictionaries give good advice:
-#BEQU
-**uomo**, pl. //uomini//, n.m. "man"
-#ENQU
-tells that //uomo// is a masculine noun with the plural form //uomini//.
-Hence, parametric number and an inherent gender.
-
-For words, inherent features are usually given as lexical information.
-
-For combinations, they are //inherited// from some part of the construction
-(typically the one called the **head**). Italian modification:
-```
-  lin QKind qual kind = 
-    let gen = kind.g in {
-      s = table {n => kind.s ! n ++ qual.s ! gen ! n} ;
-      g = gen
-      } ;
-```
-Notice 
-- **local definition** (``let`` expression)
-- **variable pattern** ``n``
-
-
-
-#NEW
-
-==An English concrete syntax for Foods with parameters==
-
-We use some string operations from the library ``Prelude`` are used. 
-```
-   concrete FoodsEng of Foods = open Prelude in {
-
-  lincat
-    S, Quality = SS ; 
-    Kind = {s : Number => Str} ; 
-    Item = {s : Str ; n : Number} ; 
-
-  lin
-    Is item quality = ss (item.s ++ copula item.n ++ quality.s) ;
-    This  = det Sg "this" ;
-    That  = det Sg "that" ;
-    These = det Pl "these" ;
-    Those = det Pl "those" ;
-    QKind quality kind = {s = table {n => quality.s ++ kind.s ! n}} ;
-    Wine = regNoun "wine" ;
-    Cheese = regNoun "cheese" ;
-    Fish = noun "fish" "fish" ;
-    Pizza = regNoun "pizza" ;
-    Very = prefixSS "very" ;
-    Fresh = ss "fresh" ;
-    Warm = ss "warm" ;
-    Italian = ss "Italian" ;
-    Expensive = ss "expensive" ;
-    Delicious = ss "delicious" ;
-    Boring = ss "boring" ;
-```
-
-#NEW
-
-```
-  param
-    Number = Sg | Pl ;
-
-  oper
-    det : Number -> Str -> {s : Number => Str} -> {s : Str ; n : Number} = 
-      \n,d,cn -> {
-        s = d ++ cn.s ! n ;
-        n = n
-      } ;
-    noun : Str -> Str -> {s : Number => Str} = 
-      \man,men -> {s = table {
-        Sg => man ;
-        Pl => men 
-        }
-      } ;
-    regNoun : Str -> {s : Number => Str} = 
-      \car -> noun car (car + "s") ;
-    copula : Number -> Str = 
-      \n -> case n of {
-        Sg => "is" ;
-        Pl => "are"
-        } ;
-  }    
-```
-
-#NEW
-
-==More on inflection paradigms==
-
-#Lsecinflection
-
-Let us extend the English noun paradigms so that we can
-deal with all nouns, not just the regular ones. The goal is to
-provide a morphology module that makes it easy to
-add words to a lexicon. 
-
-
-#NEW
-
-===Worst-case functions===
-
-We perform **data abstraction** from the type
-of nouns by writing a a **worst-case function**:
-```
-  oper Noun : Type = {s : Number => Str} ;
-
-  oper mkNoun : Str -> Str -> Noun = \x,y -> {
-    s = table {
-      Sg => x ;
-      Pl => y
-      }
-    } ;
-
-  oper regNoun : Str -> Noun = \x -> mkNoun x (x + "s") ;
-```
-Then we can define
-```
-  lincat N = Noun ;
-  lin Mouse = mkNoun "mouse" "mice" ;
-  lin House = regNoun "house" ;
-```
-where the underlying types are not seen.
-
-#NEW
-
-We are free to change the undelying definitions, e.g.
-add **case** (nominative or genitive) to noun inflection:
-```
-  param Case = Nom | Gen ;
-
-  oper Noun : Type = {s : Number => Case => Str} ;
-```
-Now we have to redefine the worst-case function
-```
-  oper mkNoun : Str -> Str -> Noun = \x,y -> {
-    s = table {
-      Sg => table {
-        Nom => x ;
-        Gen => x + "'s"
-        } ;
-      Pl => table {
-        Nom => y ;
-        Gen => y + case last y of {
-          "s" => "'" ;
-          _   => "'s"
-        }
-      }
-    } ;
-```
-But up from this level, we can retain the old definitions
-```
-  lin Mouse = mkNoun "mouse" "mice" ;
-  oper regNoun : Str -> Noun = \x -> mkNoun x (x + "s") ;
-```
-
-
-
-#NEW
-
-In the last definition of ``mkNoun``, we used a case expression
-on the last character of the plural, as well as the ``Prelude`` 
-operation
-```
-  last : Str -> Str ;
-```
-returning the string consisting of the last character.
-
-The case expression uses **pattern matching over strings**, which
-is supported in GF, alongside with pattern matching over
-parameters.
-
-
-
-#NEW
-
-===Smart paradigms===
-
-The regular //dog//-//dogs// paradigm has
-predictable variations:
-- nouns ending with an //y//: //fly//-//flies//, except if
-  a vowel precedes the //y//: //boy//-//boys//
-- nouns ending with //s//, //ch//, and a number of
-  other endings: //bus//-//buses//, //leech//-//leeches//
-
-
-We could provide alternative paradigms:
-```
-  noun_y : Str -> Noun = \fly -> mkNoun fly (init fly + "ies") ;  
-  noun_s : Str -> Noun = \bus -> mkNoun bus (bus + "es") ;
-```
-(The Prelude function ``init`` drops the last character of a token.)
-
-Drawbacks: 
-- it can be difficult to select the correct paradigm
-- it can be difficult to remember the names of the different paradigms
-
-
-#NEW
-
-Better solution: a **smart paradigm**:
-```
-  regNoun : Str -> Noun = \w -> 
-    let 
-      ws : Str = case w of {
-        _ + ("a" | "e" | "i" | "o") + "o" => w + "s" ;  -- bamboo
-        _ + ("s" | "x" | "sh" | "o")      => w + "es" ; -- bus, hero
-        _ + "z"                           => w + "zes" ;-- quiz 
-        _ + ("a" | "e" | "o" | "u") + "y" => w + "s" ;  -- boy
-        x + "y"                           => x + "ies" ;-- fly
-        _                                 => w + "s"    -- car
-        } 
-    in 
-    mkNoun w ws
-```
-GF has **regular expression patterns**:
-- **disjunctive patterns**  //P// ``|`` //Q//
-- **concatenation patterns** //P// ``+`` //Q//
-
-
-The patterns are ordered in such a way that, for instance, 
-the suffix ``"oo"`` prevents //bamboo// from matching the suffix
-``"o"``.
-
-
-#NEW
-
-===Exercises on regular patterns===
-
-+ The same rules that form plural nouns in English also
-apply in the formation of third-person singular verbs. 
-Write a regular verb paradigm that uses this idea, but first
-rewrite ``regNoun`` so that the analysis needed to build //s//-forms
-is factored out as a separate ``oper``, which is shared with
-``regVerb``.
-
-+ Extend the verb paradigms to cover all verb forms
-in English, with special care taken of variations with the suffix
-//ed// (e.g. //try//-//tried//, //use//-//used//).
-
-+ Implement the German **Umlaut** operation on word stems.
-The operation changes the vowel of the stressed stem syllable as follows:
-//a// to //ä//, //au// to //äu//, //o// to //ö//, and //u// to //ü//. You
-can assume that the operation only takes syllables as arguments. Test the
-operation to see whether it correctly changes //Arzt// to //Ärzt//,
-//Baum// to //Bäum//, //Topf// to //Töpf//, and //Kuh// to //Küh//.
-
-
-
-#NEW
-
-===Function types with variables===
-
-In #Rchapsix, **dependent function types** need a notation
-that binds a variable to the argument type, as in
-```
-  switchOff : (k : Kind) -> Action k
-```
-Function types //without// variables are actually a shorthand:
-```
-  PredVP : NP -> VP -> S
-```
-means
-```
-  PredVP : (x : NP) -> (y : VP) -> S
-```
-or any other naming of the variables.
-
-
-#NEW
-
-Sometimes variables shorten the code, since they can share a type:
-```
-  octuple : (x,y,z,u,v,w,s,t : Str) -> Str
-```
-If a bound variable is not used, it can be replaced by a wildcard:
-```
-  octuple : (_,_,_,_,_,_,_,_ : Str) -> Str
-```
-A good practice is to indicate the number of arguments:
-```
-  octuple : (x1,_,_,_,_,_,_,x8 : Str) -> Str
-```
-For inflection paradigms, it is handy to use heuristic variable names,
-looking like the expected forms:
-```
-  mkNoun : (mouse,mice : Str) -> Noun
-```
-
-
-#NEW
-
-===Separating operation types and definitions===
-
-In librarues, it is useful to group type signatures separately from
-definitions. It is possible to divide an ``oper`` judgement, 
-```
-  oper regNoun : Str -> Noun ;
-  oper regNoun s = mkNoun s (s + "s") ;
-```
-and put the parts in different places.
-
-With the ``interface`` and ``instance`` module types
-(see #Rsecinterface): the parts can even be put to different files.
-
-
-#NEW
-
-===Overloading of operations===
-
-**Overloading**: different functions can be given the same name, as e.g. in C++.
-
-The compiler performs **overload resolution**, which works as long as the
-functions have different types.
-
-In GF, the functions must be grouped together in ``overload`` groups. 
-
-Example: different ways to define nouns in English:
-```
-  oper mkN : overload {
-    mkN : (dog : Str) -> Noun ;         -- regular nouns
-    mkN : (mouse,mice : Str) -> Noun ;  -- irregular nouns
-  }
-```
-Cf. dictionaries: if the
-word is regular, just one form is needed. If it is irregular,
-more forms are given. 
-
-The definition can be given separately, or at the same time, as the types:
-```
-  oper mkN = overload {
-    mkN : (dog : Str) -> Noun = regNoun ;
-    mkN : (mouse,mice : Str) -> Noun = mkNoun ;
-  }
-```
-**Exercise**. Design a system of English verb paradigms presented by
-an overload group.
-
-
-#NEW
-
-===Morphological analysis and morphology quiz===
-
-The command ``morpho_analyse = ma``
-can be used to read a text and return for each word its analyses
-(in the current grammar):
-```
-  > read_file bible.txt | morpho_analyse
-```
-The command ``morpho_quiz = mq`` generates inflection exercises. 
-```
-  % gf -path=alltenses:prelude $GF_LIB_PATH/alltenses/IrregFre.gfc
-
-  > morpho_quiz -cat=V
-
-  Welcome to GF Morphology Quiz.
-  ...
-
-  réapparaître : VFin VCondit  Pl  P2
-  réapparaitriez
-  > No, not réapparaitriez, but
-  réapparaîtriez
-  Score 0/1
-```
-To create a list for later use, use the command ``morpho_list = ml``
-```
-  > morpho_list -number=25 -cat=V | write_file exx.txt
-```
-
-
-
-
-#NEW
-
-==The Italian Foods grammar==
-
-#Lsecitalian
-
-Parameters include not only number but also gender.
-```
-concrete FoodsIta of Foods = open Prelude in {
-
-  param
-    Number = Sg | Pl ;
-    Gender = Masc | Fem ;
-```
-Qualities are inflected for gender and number, whereas kinds
-have a parametric number and an inherent gender.
-Items have an inherent number and gender.
-```
-  lincat
-    Phr = SS ; 
-    Quality = {s : Gender => Number => Str} ; 
-    Kind = {s : Number => Str ; g : Gender} ; 
-    Item = {s : Str ; g : Gender ; n : Number} ; 
-```
-
-#NEW
-
-A Quality is an adjective, with one form for each gender-number combination.
-```
-  oper
-    adjective : (_,_,_,_ : Str) -> {s : Gender => Number => Str} = 
-      \nero,nera,neri,nere -> {
-        s = table {
-          Masc => table {
-            Sg => nero ;
-            Pl => neri
-            } ; 
-          Fem => table {
-            Sg => nera ;
-            Pl => nere
-            }
-          }
-      } ;
-```
-Regular adjectives work by adding endings to the stem.
-```
-    regAdj : Str -> {s : Gender => Number => Str} = \nero ->
-      let ner = init nero 
-      in adjective nero (ner + "a") (ner + "i") (ner + "e") ;
-```
-
-#NEW
-
-For noun inflection, we are happy to give the two forms and the gender 
-explicitly:
-```
-    noun : Str -> Str -> Gender -> {s : Number => Str ; g : Gender} = 
-      \vino,vini,g -> {
-        s = table {
-          Sg => vino ;
-          Pl => vini
-          } ;
-        g = g
-      } ;
-```
-We need only number variation for the copula.
-```
-    copula : Number -> Str = 
-      \n -> case n of {
-        Sg => "è" ;
-        Pl => "sono"
-        } ;
-```
-
-#NEW
-
-Determination is more complex than in English, because of gender:
-```
-    det : Number -> Str -> Str -> {s : Number => Str ; g : Gender} -> 
-        {s : Str ; g : Gender ; n : Number} = 
-      \n,m,f,cn -> {
-        s = case cn.g of {Masc => m ; Fem => f} ++ cn.s ! n ;
-        g = cn.g ;
-        n = n
-      } ;
-```
-
-
-#NEW
-
-The complete set of linearization rules:
-```
-  lin
-    Is item quality = 
-      ss (item.s ++ copula item.n ++ quality.s ! item.g ! item.n) ;
-    This  = det Sg "questo" "questa" ;
-    That  = det Sg "quel"   "quella" ;
-    These = det Pl "questi" "queste" ;
-    Those = det Pl "quei"   "quelle" ;
-    QKind quality kind = {
-      s = \\n => kind.s ! n ++ quality.s ! kind.g ! n ;
-      g = kind.g
-      } ;
-    Wine = noun "vino" "vini" Masc ;
-    Cheese = noun "formaggio" "formaggi" Masc ;
-    Fish = noun "pesce" "pesci" Masc ;
-    Pizza = noun "pizza" "pizze" Fem ;
-    Very qual = {s = \\g,n => "molto" ++ qual.s ! g ! n} ;
-    Fresh = adjective "fresco" "fresca" "freschi" "fresche" ;
-    Warm = regAdj "caldo" ;
-    Italian = regAdj "italiano" ;
-    Expensive = regAdj "caro" ;
-    Delicious = regAdj "delizioso" ;
-    Boring = regAdj "noioso" ;
-  }
-```
-
-
-#NEW
-
-===Exercises on using parameters===
-
-+ Experiment with multilingual generation and translation in the
-``Foods`` grammars.
-
-+ Add items, qualities, and determiners to the grammar, 
-and try to get their inflection and inherent features right.
-
-+ Write a concrete syntax of ``Food`` for a language of your choice,
-now aiming for complete grammatical correctness by the use of parameters.
-
-+ Measure the size of the context-free grammar corresponding to
-``FoodsIta``. You can do this by printing the grammar in the context-free format
-(``print_grammar -printer=bnf``) and counting the lines.
-
-
-
-
-#NEW
-
-==Discontinuous constituents==
-
-A linearization record may contain more strings than one, and those
-strings can be put apart in linearization.
-
-Example: English particle
-verbs, (//switch off//). The object can appear between:
-
-//he switched it off//
-
-The verb //switch off// is called a
-**discontinuous constituents**.
-
-We can define transitive verbs and their combinations as follows:
-```
-  lincat TV = {s : Number => Str ; part : Str} ;
-
-  fun AppTV : Item -> TV -> Item -> Phrase ;
-
-  lin AppTV subj tv obj = 
-    {s = subj.s ++ tv.s ! subj.n ++ obj.s ++ tv.part} ;
-```
-
-**Exercise**. Define the language ``a^n b^n c^n`` in GF, i.e.
-any number of //a//'s followed by the same number of //b//'s and
-the same number of //c//'s. This language is not context-free,
-but can be defined in GF by using discontinuous constituents.
-
-
-#NEW
-
-==Strings at compile time vs. run time==
-
-Tokens are created in the following ways:
-- quoted string: ``"foo"``
-- gluing : ``t + s``
-- predefined operations ``init, tail, tk, dp``
-- pattern matching over strings
-
-
-Since //tokens must be known at compile time//,
-the above operations may not be applied to **run-time variables**
-(i.e. variables that stand for function arguments in linearization rules).
-
-Hence it is not legal to write
-```
-  cat Noun ;
-  fun Plural : Noun -> Noun ;
-  lin Plural n = {s = n.s + "s"} ;
-```
-because ``n`` is a run-time variable. Also
-```
-  lin Plural n = {s = (regNoun n).s ! Pl} ; 
-```
-is incorrect with ``regNoun`` as defined #Rsecinflection, because the run-time 
-variable is eventually sent to string pattern matching and gluing.
-
-
-#NEW
-
-How to write tokens together without a space?
-```
-  lin Question p = {s = p + "?"} ;
-```
-is incorrect. 
-
-The way to go is to use an **unlexer** that creates correct spacing
-after linearization. 
-
-Correspondingly, a **lexer** that e.g. analyses ``"warm?"`` into
-to tokens is needed before parsing. 
-This topic will be covered in #Rseclexing.
-
-
-
-
-
-
-#NEW
-
-===Supplementary constructs for concrete syntax===
-
-====Record extension and subtyping====
-
-The symbol ``**`` is used for both record types and record objects.
-```
-  lincat TV = Verb ** {c : Case} ;
-
-  lin Follow = regVerb "folgen" ** {c = Dative} ; 
-```
-``TV`` becomes a **subtype** of ``Verb``.
-
-If //T// is a subtype of //R//, an object of //T// can be used whenever
-an object of //R// is required. 
-
-**Covariance**: a function returning a record //T// as value can
-also be used to return a value of a supertype //R//.
-
-**Contravariance**: a function taking an //R// as argument
-can also be applied to any object of a subtype //T//.
-
-
-#NEW
-
-====Tuples and product types====
-
-Product types and tuples are syntactic sugar for record types and records:
-```
-  T1 * ... * Tn   ===   {p1 : T1 ; ... ; pn : Tn}
-  <t1, ...,  tn>  ===   {p1 = T1 ; ... ; pn = Tn}
-```
-Thus the labels ``p1, p2,...`` are hard-coded.
-
-
-#NEW
-
-====Prefix-dependent choices====
-
-English indefinite article:
-```
-  oper artIndef : Str = 
-    pre {"a" ; "an" / strs {"a" ; "e" ; "i" ; "o"}} ;
-```
-Thus
-```
-  artIndef ++ "cheese"  --->  "a" ++ "cheese"
-  artIndef ++ "apple"   --->  "an" ++ "apple"
-```
-
-
-
-
-
-
-
-
-#NEW
-
-=Lesson 4: Using the resource grammar library=
-
-#Lchapfive
-
-Goals:
-- navigate in the GF resource grammar library and use it in applications
-- get acquainted with basic linguistic categories
-- write functors to achieve maximal sharing of code in multilingual grammars
-
-
-#NEW
-
-==The coverage of the library==
-
-The current 12 resource languages are
-- ``Bul``garian
-- ``Cat``alan
-- ``Dan``ish
-- ``Eng``lish
-- ``Fin``nish
-- ``Fre``nch
-- ``Ger``man
-- ``Ita``lian
-- ``Nor``wegian
-- ``Rus``sian
-- ``Spa``nish
-- ``Swe``dish
-
-
-The first three letters (``Eng`` etc) are used in grammar module names
-(ISO 639 standard).
-
-
-#NEW
-
-==The structure of the library==
-
-#Lseclexical
-
-Semantic grammars (up to now in this tutorial):
-a grammar defines a system of meanings (abstract syntax) and
-tells how they are expressed(concrete syntax).
-
-Resource grammars (as usual in linguistic tradition):
-a grammar specifies the **grammatically correct combinations of words**, 
-whatever their meanings are. 
-
-With resource grammars, we can achieve a
-wider coverage than with semantic grammars.
-
-#NEW
-
-===Lexical vs. phrasal rules===
-
-A resource grammar has two kinds of categories and two kinds of rules:
-- lexical:
-  - lexical categories, to classify words
-  - lexical rules, to define words and their properties
-
-- phrasal (combinatorial, syntactic):
-  - phrasal categories, to classify phrases of arbitrary size
-  - phrasal rules, to combine phrases into larger phrases
-
-
-GE makes no formal distinction between these two kinds.
-
-But it is a good discipline to follow.
-
-
-#NEW
-
-===Lexical categories===
-
-Two kinds of lexical categories:
-- **closed**: 
-  - a finite number of words
-  - seldom extended in the history of language
-  - structural words / function words, e.g.
-```
-    Conj ;     -- conjunction           e.g. "and"
-    QuantSg ;  -- singular quantifier   e.g. "this"
-    QuantPl ;  -- plural quantifier     e.g. "this"
-```
-
-- **open**:
-  - new words are added all the time
-  - content words, e.g.
-```
-    N ;        -- noun         e.g. "pizza"
-    A ;        -- adjective    e.g. "good"
-    V ;        -- verb         e.g. "sleep"
-```
-
-
-#NEW
-
-===Lexical rules===
-
-Closed classes: module ``Syntax``. In the ``Foods`` grammar, we need
-```
-  this_QuantSg, that_QuantSg : QuantSg ; 
-  these_QuantPl, those_QuantPl : QuantPl ; 
-  very_AdA  : AdA ;
-```
-Naming convention: word followed by the category (so we can
-distinguish the quantifier //that// from the conjunction //that//). 
-
-Open classes have no objects in ``Syntax``. Words are
-built as they are needed in applications: if we have
-```
-  fun Wine : Kind ;
-```
-we will define
-```
-  lin Wine = mkN "wine" ;
-```
-where we use ``mkN`` from ``ParadigmsEng``:
-
-
-
-#NEW
-
-===Resource lexicon===
-
-Alternative concrete syntax for
-```
-  fun Wine : Kind ;
-```
-is to provide a **resource lexicon**, which contains definitions such as
-```
-  oper wine_N : N = mkN "wine" ;
-```
-so that we can write
-```
-  lin Wine = wine_N ;
-```
-Advantages:
-- we accumulate a reusable lexicon
-- we can use a #Rsecfunctor to speed up multilingual grammar implementation
-
-
-#NEW
-
-===Phrasal categories===
-
-In ``Foods``, we need just four phrasal categories:
-```
-  Cl ;   -- clause             e.g. "this pizza is good"
-  NP ;   -- noun phrase        e.g. "this pizza"
-  CN ;   -- common noun        e.g. "warm pizza"
-  AP ;   -- adjectival phrase  e.g. "very warm"
-```
-Clauses are similar to sentences (``S``), but without a
-fixed tense and mood; see #Rsecextended for how they relate.
-
-Common nouns are made into noun phrases by adding determiners.
-
-
-#NEW
-
-===Syntactic combinations===
-
-We need the following combinations:
-```
-  mkCl : NP -> AP -> Cl ;      -- e.g. "this pizza is very warm"
-  mkNP : QuantSg -> CN -> NP ; -- e.g. "this pizza" 
-  mkNP : QuantPl -> CN -> NP ; -- e.g. "these pizzas"
-  mkCN : AP -> CN -> CN ;      -- e.g. "warm pizza"
-  mkAP : AdA -> AP -> AP ;     -- e.g. "very warm" 
-```
-We also need **lexical insertion**, to form phrases from single words:
-```
-  mkCN : N -> NP ;
-  mkAP : A -> AP ;
-```
-Naming convention: to construct a //C//, use a function ``mk``//C//.
-
-Heavy overloading: the current library
-(version 1.2) has 23 operations named ``mkNP``!
-
-
-#NEW
-
-===Example syntactic combination===
-
-The sentence
-#BEQU
-//these very warm pizzas are Italian//
-#ENQU
-can be built as follows:
-```
-  mkCl 
-    (mkNP these_QuantPl 
-       (mkCN (mkAP very_AdA (mkAP warm_A)) (mkCN pizza_CN)))
-    (mkAP italian_AP) 
-```
-The task now: to define the concrete syntax of ``Foods`` so that
-this syntactic tree gives the value of linearizing the semantic tree
-```
-  Is (These (QKind (Very Warm) Pizza)) Italian
-```
-
-
-
-#NEW
-
-==The resource API==
-
-Language-specific and language-independent parts - roughly,
-- the syntax API ``Syntax``//L// has the same types and 
-  functions for all languages //L//
-- the morphology API ``Paradigms``//L// has partly 
-  different types and functions
-  for different languages //L//
-
-
-Full API documentation on-line: the **resource synopsis**,
-
-[``digitalgrammars.com/gf/lib/resource/doc/synopsis.html`` http://digitalgrammars.com/gf/lib/resource/doc/synopsis.html]
-
-
-#NEW
-
-===A miniature resource API: categories===
-
-|| Category  | Explanation  | Example  ||
-| ``Cl``  | clause (sentence), with all tenses | //she looks at this// |
-| ``AP`` | adjectival phrase | //very warm// |
-| ``CN`` | common noun (without determiner) | //red house// |
-| ``NP`` | noun phrase (subject or object) | //the red house// |
-| ``AdA`` | adjective-modifying adverb, | //very// |
-| ``QuantSg`` | singular quantifier | //these// |
-| ``QuantPl`` | plural quantifier | //this// |
-| ``A`` | one-place adjective | //warm// |
-| ``N`` | common noun | //house// |
-
-
-#NEW
-
-===A miniature resource API: rules===
-
-|| Function  | Type  | Example  ||
-| ``mkCl``  | ``NP -> AP -> Cl`` | //John is very old// |
-| ``mkNP``  | ``QuantSg -> CN -> NP`` | //this old man// |
-| ``mkNP``  | ``QuantPl -> CN -> NP`` | //these old man// |
-| ``mkCN``  | ``N -> CN`` | //house// |
-| ``mkCN``  | ``AP -> CN -> CN`` | //very big blue house// |
-| ``mkAP``  | ``A -> AP`` | //old// |
-| ``mkAP``  | ``AdA -> AP -> AP`` | //very very old// |
-
-#NEW
-
-===A miniature resource API: structural words===
-
-|| Function      | Type       | In English  ||
-| ``this_QuantSg`` | ``QuantSg``  | //this// |
-| ``that_QuantSg`` | ``QuantSg``  | //that// |
-| ``these_QuantPl`` | ``QuantPl``  | //this// |
-| ``those_QuantPl`` | ``QuantPl``  | //that// |
-| ``very_AdA``   | ``AdA``    | //very// |
-
-
-#NEW
-
-===A miniature resource API: paradigms===
-
-From ``ParadigmsEng``:
-
-|| Function  | Type  ||
-| ``mkN`` | ``(dog : Str) -> N`` | 
-| ``mkN`` | ``(man,men : Str) -> N`` | 
-| ``mkA`` | ``(cold : Str) -> A`` | 
-
-From ``ParadigmsIta``:
-
-|| Function  | Type  ||
-| ``mkN`` | ``(vino : Str) -> N`` | 
-| ``mkA`` | ``(caro : Str) -> A`` | 
-
-
-#NEW
-
-===A miniature resource API: more paradigms===
-
-From ``ParadigmsGer``:
-
-|| Function  | Type  ||
-| ``Gender`` | ``Type`` | 
-| ``masculine`` | ``Gender`` |
-| ``feminine`` | ``Gender`` |
-| ``neuter`` | ``Gender`` | 
-| ``mkN`` | ``(Stufe : Str) -> N`` | 
-| ``mkN`` | ``(Bild,Bilder : Str) -> Gender -> N`` |
-| ``mkA`` | ``(klein : Str) -> A`` |
-| ``mkA`` | ``(gut,besser,beste : Str) -> A`` |
-
-From ``ParadigmsFin``:
-
-|| Function  | Type  ||
-| ``mkN`` | ``(talo : Str) -> N`` | 
-| ``mkA`` | ``(hieno : Str) -> A`` | 
-
-
-
-#NEW
-
-===Exercises===
-
-1. Try out the morphological paradigms in different languages. Do 
-as follows:
-```
-  > i -path=alltenses -retain alltenses/ParadigmsGer.gfo
-  > cc -table mkN "Farbe"
-  > cc -table mkA "gut" "besser" "beste"
-```
-
-
-#NEW
-
-==Example: English==
-
-#Lsecenglish
-
-We assume the abstract syntax ``Foods`` from #Rchapfour.
-
-We don't need to think about inflection and agreement, but just pick
-functions from the resource grammar library.
-
-We need a path with
-- the current directory ``.`` 
-- the directory ``../foods``, in which ``Foods.gf`` resides.
-- the library directory ``present``, which is relative to the 
-  environment variable ``GF_LIB_PATH``
-
-
-Thus the beginning of the module is
-```
-  --# -path=.:../foods:present
-
-  concrete FoodsEng of Foods = open SyntaxEng,ParadigmsEng in {
-```
-
-
-#NEW
-
-===English example: linearization types and combination rules===
-
-As linearization types, we use clauses for ``Phrase``, noun phrases
-for ``Item``, common nouns for ``Kind``, and adjectival phrases for ``Quality``.
-```
-  lincat
-    Phrase = Cl ; 
-    Item = NP ;
-    Kind = CN ;
-    Quality = AP ;
-```
-Now the combination rules we need almost write themselves automatically:
-```
-  lin
-    Is item quality = mkCl item quality ;
-    This kind = mkNP this_QuantSg kind ;
-    That kind = mkNP that_QuantSg kind ;
-    These kind = mkNP these_QuantPl kind ;
-    Those kind = mkNP those_QuantPl kind ;
-    QKind quality kind = mkCN quality kind ;
-    Very quality = mkAP very_AdA quality ;
-```
-
-
-#NEW
-
-===English example: lexical rules===
-
-We use resource paradigms and lexical insertion rules.
-
-The two-place noun paradigm is needed only once, for
-//fish// - everythins else is regular.
-```
-    Wine = mkCN (mkN "wine") ;
-    Pizza = mkCN (mkN "pizza") ;
-    Cheese = mkCN (mkN "cheese") ;
-    Fish = mkCN (mkN "fish" "fish") ;
-    Fresh = mkAP (mkA "fresh") ;
-    Warm = mkAP (mkA "warm") ;
-    Italian = mkAP (mkA "Italian") ;
-    Expensive = mkAP (mkA "expensive") ;
-    Delicious = mkAP (mkA "delicious") ;
-    Boring = mkAP (mkA "boring") ;
-  }
-```
-
-
-#NEW
-
-===English example: exercises===
-
-1. Compile the grammar ``FoodsEng`` and generate 
-and parse some sentences.
-
-2. Write a concrete syntax of ``Foods`` for Italian 
-or some other language included in the resource library. You can 
-compare the results with the hand-written
-grammars presented earlier in this tutorial.
-
-
-
-#NEW
-
-==Functor implementation of multilingual grammars==
-
-#Lsecfunctor
-
-===New language by copy and paste===
-
-If you write  a concrete syntax of ``Foods`` for some other
-language, much of the code will look exactly the same
-as for English. This is because 
-- the ``Syntax`` API is the same for all languages (because
-  all languages in the resource package do implement the same 
-  syntactic structures) 
-- languages tend to use the syntactic structures in similar ways
-
-
-But lexical rules are more language-dependent.
-
-Thus, to port a grammar to a new language, you
-+ copy the concrete syntax of a given language
-+ change the words (strings and inflection paradigms)
-
-
-Can we avoid this programming by copy-and-paste?
-
-
-
-#NEW
-
-===Functors: functions on the module level===
-
-**Functors** familiar from the functional programming languages ML and OCaml, 
-also known as **parametrized modules**.
-
-In GF, a functor is a module that ``open``s one or more **interfaces**.
-
-An ``interface`` is a module similar to a ``resource``, but it only
-contains the //types// of ``oper``s, not (necessarily) their definitions. 
-
-Syntax for functors: add the keyword ``incomplete``. We will use the header
-```
-  incomplete concrete FoodsI of Foods = open Syntax, LexFoods in
-```
-where
-```
-  interface Syntax    -- the resource grammar interface
-  interface LexFoods  -- the domain lexicon interface
-```
-When we moreover have
-```
-  instance SyntaxEng of Syntax     -- the English resource grammar
-  instance LexFoodsEng of LexFoods -- the English domain lexicon
-```
-we can write a **functor instantiation**,
-```
-  concrete FoodsGer of Foods = FoodsI with 
-    (Syntax = SyntaxGer),
-    (LexFoods = LexFoodsGer) ;
-```
-
-#NEW
-
-===Code for the Foods functor===
-
-```
-  --# -path=.:../foods
-
-  incomplete concrete FoodsI of Foods = open Syntax, LexFoods in {
-  lincat
-    Phrase = Cl ; 
-    Item = NP ;
-    Kind = CN ;
-    Quality = AP ;
-  lin
-    Is item quality = mkCl item quality ;
-    This kind = mkNP this_QuantSg kind ;
-    That kind = mkNP that_QuantSg kind ;
-    These kind = mkNP these_QuantPl kind ;
-    Those kind = mkNP those_QuantPl kind ;
-    QKind quality kind = mkCN quality kind ;
-    Very quality = mkAP very_AdA quality ;
-
-    Wine = mkCN wine_N ;
-    Pizza = mkCN pizza_N ;
-    Cheese = mkCN cheese_N ;
-    Fish = mkCN fish_N ;
-    Fresh = mkAP fresh_A ;
-    Warm = mkAP warm_A ;
-    Italian = mkAP italian_A ;
-    Expensive = mkAP expensive_A ;
-    Delicious = mkAP delicious_A ;
-    Boring = mkAP boring_A ;
-  }
-```
-
-
-#NEW
-
-===Code for the LexFoods interface===
-
-#Lsecinterface
-
-```
-  interface LexFoods = open Syntax in {
-  oper
-    wine_N : N ;
-    pizza_N : N ;
-    cheese_N : N ;
-    fish_N : N ;
-    fresh_A : A ;
-    warm_A : A ;
-    italian_A : A ;
-    expensive_A : A ;
-    delicious_A : A ;
-    boring_A : A ;
-  }
-```
-
-#NEW
-
-===Code for a German instance of the lexicon===
-
-```
-  instance LexFoodsGer of LexFoods = open SyntaxGer, ParadigmsGer in {
-  oper
-    wine_N = mkN "Wein" ;
-    pizza_N = mkN "Pizza" "Pizzen" feminine ;
-    cheese_N = mkN "Käse" "Käsen" masculine ;
-    fish_N = mkN "Fisch" ;
-    fresh_A = mkA "frisch" ;
-    warm_A = mkA "warm" "wärmer" "wärmste" ;
-    italian_A = mkA "italienisch" ;
-    expensive_A = mkA "teuer" ;
-    delicious_A = mkA "köstlich" ;
-    boring_A = mkA "langweilig" ;
-  }
-```
-
-
-#NEW
-
-===Code for a German functor instantiation===
-
-```
-  --# -path=.:../foods:present
-
-  concrete FoodsGer of Foods = FoodsI with 
-    (Syntax = SyntaxGer),
-    (LexFoods = LexFoodsGer) ;
-```
-
-
-
-#NEW
-
-===Adding languages to a functor implementation===
-
-Just two modules are needed:
-- a domain lexicon instance
-- a functor instantiation
-
-
-The functor instantiation is completely mechanical to write.
-
-The domain lexicon instance requires some knowledge of the words of the
-language: 
-- what words are used for which concepts
-- how the words are
-- features such as genders
-
-
-#NEW
-
-===Example: adding Finnish===
-
-Lexicon instance
-```
-  instance LexFoodsFin of LexFoods = open SyntaxFin, ParadigmsFin in {
-  oper
-    wine_N = mkN "viini" ;
-    pizza_N = mkN "pizza" ;
-    cheese_N = mkN "juusto" ;
-    fish_N = mkN "kala" ;
-    fresh_A = mkA "tuore" ;
-    warm_A = mkA "lämmin" ;
-    italian_A = mkA "italialainen" ;
-    expensive_A = mkA "kallis" ;
-    delicious_A = mkA "herkullinen" ;
-    boring_A = mkA "tylsä" ;
-  }
-```
-Functor instantiation
-```
-  --# -path=.:../foods:present
-
-  concrete FoodsFin of Foods = FoodsI with 
-    (Syntax = SyntaxFin),
-    (LexFoods = LexFoodsFin) ;
-```
-
-
-#NEW
-
-===A design pattern===
-
-This can be seen as a //design pattern// for multilingual grammars:
-```
-                      concrete DomainL*
-
-    instance LexDomainL                 instance SyntaxL*
-   
-                 incomplete concrete DomainI
-                 /           |              \               
-   interface LexDomain   abstract Domain    interface Syntax*
-```
-Modules marked with ``*`` are either given in the library, or trivial.
-
-Of the hand-written modules, only ``LexDomainL`` is language-dependent.
-
-
-#NEW
-
-===Functors: exercises===
-
-1. Compile and test ``FoodsGer``.
-
-2. Refactor ``FoodsEng`` into a functor instantiation.
-
-3. Instantiate the functor ``FoodsI`` to some language of
-your choice.
-
-4. Design a small grammar that can be used for controlling
-an MP3 player. The grammar should be able to recognize commands such
-as //play this song//, with the following variations:
-- verbs: //play//, //remove//
-- objects: //song//, //artist//
-- determiners: //this//, //the previous//
-- verbs without arguments: //stop//, //pause//
-
-
-The implementation goes in the following phases:
-+ abstract syntax
-+ (optional:) prototype string-based concrete syntax
-+ functor over resource syntax and lexicon interface
-+ lexicon instance for the first language
-+ functor instantiation for the first language
-+ lexicon instance for the second language
-+ functor instantiation for the second language
-+ ...
-
-
-
-#NEW
-
-==Restricted inheritance==
-
-===A problem with functors===
-
-Problem: a functor only works when all languages use the resource ``Syntax`` 
-in the same way.
-
-Example (contrived): assume that English has
-no word for ``Pizza``, but has to use the paraphrase //Italian pie//.
-This is no longer a noun ``N``, but a complex phrase
-in the category ``CN``. 
-
-Possible solution: change interface the ``LexFoods`` with
-```
-  oper pizza_CN : CN ;
-```
-Problem with this solution: 
-- we may end up changing the interface and the function with each new language
-- we must every time also change the instances for the old languages to maintain
-  type correctness
-
-
-#NEW
-
-===Restricted inheritance: include or exclude===
-
-A module may inherit just a selection of names.
-
-Example: the ``FoodMarket`` example "Rsecarchitecture:
-```
-  abstract Foodmarket = Food, Fruit [Peach], Mushroom - [Agaric]
-```
-Here, from ``Fruit`` we include ``Peach`` only, and from ``Mushroom``
-we exclude ``Agaric``.
-
-A concrete syntax of ``Foodmarket`` must make the analogous restrictions.
-
-
-#NEW
-
-===The functor problem solved===
-
-The English instantiation inherits the functor 
-implementation except for the constant ``Pizza``. This constant
-is defined in the body instead:
-```
-  --# -path=.:../foods:present
-
-  concrete FoodsEng of Foods = FoodsI - [Pizza] with 
-    (Syntax = SyntaxEng),
-    (LexFoods = LexFoodsEng) ** 
-      open SyntaxEng, ParadigmsEng in {
-
-    lin Pizza = mkCN (mkA "Italian") (mkN "pie") ;
-  }
-```
- 
-
-#NEW
-
-==Grammar reuse==
-
-Abstract syntax modules can be used as interfaces, 
-and concrete syntaxes as their instances.
- 
-The following correspondencies are then applied:
-```
-  cat C         <--->  oper C : Type
-
-  fun f : A     <--->  oper f : A
-
-  lincat C = T  <--->  oper C : Type = T
-
-  lin f = t     <--->  oper f : A = t
-```
-
-
-
-
-#NEW
-
-===Library exercises===
-
-1. Find resource grammar terms for the following
-English phrases (in the category ``Phr``). You can first try to
-build the terms manually.
-
-//every man loves a woman//
-
-//this grammar speaks more than ten languages//
-
-//which languages aren't in the grammar//
-
-//which languages did you want to speak//
-
-
-Then translate the phrases to other languages.
-
-
-#NEW
-
-==Tenses==
-
-#Lsectense
-
-In ``Foods`` grammars, we have used the path
-```
-  --# -path=.:../foods
-```
-The library subdirectory ``present`` is a restricted version
-of the resource, with only present tense of verbs and sentences.
-
-By just changing the path, we get all tenses:
-```
-  --# -path=.:../foods:alltenses
-```
-Now we can see all the tenses of phrases, by using the ``-all`` flag 
-in linearization:
-```
-  > gr | l -all
-  This wine is delicious
-  Is this wine delicious
-  This wine isn't delicious
-  Isn't this wine delicious
-  This wine is not delicious
-  Is this wine not delicious
-  This wine has been delicious
-  Has this wine been delicious
-  This wine hasn't been delicious
-  Hasn't this wine been delicious
-  This wine has not been delicious
-  Has this wine not been delicious
-  This wine was delicious
-  Was this wine delicious
-  This wine wasn't delicious
-  Wasn't this wine delicious
-  This wine was not delicious
-  Was this wine not delicious
-  This wine had been delicious
-  Had this wine been delicious
-  This wine hadn't been delicious
-  Hadn't this wine been delicious
-  This wine had not been delicious
-  Had this wine not been delicious
-  This wine will be delicious
-  Will this wine be delicious
-  This wine won't be delicious
-  Won't this wine be delicious
-  This wine will not be delicious
-  Will this wine not be delicious
-  This wine will have been delicious
-  Will this wine have been delicious
-  This wine won't have been delicious
-  Won't this wine have been delicious
-  This wine will not have been delicious
-  Will this wine not have been delicious
-  This wine would be delicious
-  Would this wine be delicious
-  This wine wouldn't be delicious
-  Wouldn't this wine be delicious
-  This wine would not be delicious
-  Would this wine not be delicious
-  This wine would have been delicious
-  Would this wine have been delicious
-  This wine wouldn't have been delicious
-  Wouldn't this wine have been delicious
-  This wine would not have been delicious
-  Would this wine not have been delicious
-```
-We also see 
-- polarity (positive vs. negative)
-- word order (direct vs. inverted)
-- variation between contracted and full negation
-
-
-The list is even longer in languages that have more
-tenses and moods, e.g. the Romance languages.
-
-
-
-#NEW
-
-=Lesson 5: Refining semantics in abstract syntax=
-
-#Lchapsix
-
-Goals:
-- include semantic conditions in grammars, by using
-  - **dependent types** 
-  - **higher order abstract syntax** 
-  - proof objects  
-  - semantic definitions
-
-These concepts are inherited from **type theory** (more precisely:
-constructive type theory, or Martin-Löf type theory).
-
-Type theory is the basis **logical frameworks**.
-
-GF = logical framework + concrete syntax.
-
-
-#NEW
-
-==Dependent types==
-
-#Lsecsmarthouse
-
-Problem: to express **conditions of semantic well-formedness**.
-
-Example: a voice command system for a "smart house" wants to
-eliminate meaningless commands.
-
-Thus we want to restrict particular actions to
-particular devices - we can //dim a light//, but we cannot
-//dim a fan//.
-
-The following example is borrowed from the 
-Regulus Book (Rayner & al. 2006).
-
-A simple example is a "smart house" system, which
-defines voice commands for household appliances.   
-
-
-#NEW
-
-===A dependent type system===
-
-Ontology: 
-- there are commands and device kinds
-- for each kind of device, there are devices and actions
-- a command concerns an action of some kind on a device of the same kind
-
-
-Abstract syntax formalizing this:
-```
-  cat
-    Command ;
-    Kind ; 
-    Device Kind ; -- argument type Kind 
-    Action Kind ; 
-  fun 
-    CAction : (k : Kind) -> Action k -> Device k -> Command ;
-```
-``Device`` and ``Action`` are both dependent types.
-
-
-#NEW
-
-===Examples of devices and actions===
-
-Assume the kinds ``light`` and ``fan``,
-```
-  light, fan : Kind ;
-  dim : Action light ;
-```
-Given a kind, //k//, you can form the device //the k//.
-```
-  DKindOne  : (k : Kind) -> Device k ;  -- the light
-```
-Now we can form the syntax tree
-```
-  CAction light dim (DKindOne light)
-```
-but we cannot form the trees
-```
-  CAction light dim (DKindOne fan)
-  CAction fan   dim (DKindOne light)
-  CAction fan   dim (DKindOne fan)
-```
-
-
-#NEW
-
-===Linearization and parsing with dependent types===
-
-Concrete syntax does not know if a category is a dependent type. 
-```
-  lincat Action = {s : Str} ;
-  lin CAction _ act dev = {s = act.s ++ dev.s} ; 
-```
-Notice that the ``Kind`` argument is suppressed in linearization.
-
-Parsing with dependent types is performed in two phases:
-+ context-free parsing
-+ filtering through type checker
-
-
-By just doing the first phase, the ``kind`` argument is not found:
-```
-  > parse "dim the light"
-  CAction ? dim (DKindOne light)
-```
-Moreover, type-incorrect commands are not rejected:
-```
-  > parse "dim the fan"
-  CAction ? dim (DKindOne fan)
-```
-The term ``?`` is a **metavariable**, returned by the parser
-for any subtree that is suppressed by a linearization rule.
-These are the same kind of metavariables as were used #Rsecediting
-to mark incomplete parts of trees in the syntax editor.
-
-
-
-#NEW
-
-===Solving metavariables===
-
-Use the command ``put_tree = pt`` with the option ``-typecheck``:
-```
-  > parse "dim the light" | put_tree -typecheck
-  CAction light dim (DKindOne light)
-```
-The ``typecheck`` process may fail, in which case an error message
-is shown and no tree is returned:
-```
-  > parse "dim the fan" | put_tree -typecheck
-
-  Error in tree UCommand (CAction ? 0 dim (DKindOne fan)) :
-    (? 0 <> fan) (? 0 <> light)
-```
-
-
-
-
-#NEW
-
-==Polymorphism==
-
-#Lsecpolymorphic
-
-Sometimes an action can be performed on all kinds of devices. 
-
-This is represented as a function that takes a ``Kind`` as an argument 
-and produce an ``Action`` for that ``Kind``:
-```
-  fun switchOn, switchOff : (k : Kind) -> Action k ;
-```
-Functions of this kind are called **polymorphic**. 
-
-We can use this kind of polymorphism in concrete syntax as well,
-to express Haskell-type library functions:
-```
-  oper const :(a,b : Type) -> a -> b -> a =
-    \_,_,c,_ -> c ;
-
-  oper flip : (a,b,c : Type) -> (a -> b ->c) -> b -> a -> c =
-    \_,_,_,f,x,y -> f y x ;
-```
-
-
-#NEW
-
-===Dependent types: exercises===
-
-1. Write an abstract syntax module with above contents
-and an appropriate English concrete syntax. Try to parse the commands
-//dim the light// and //dim the fan//, with and without ``solve`` filtering.
-
-
-2. Perform random and exhaustive generation, with and without
-``solve`` filtering.
-
-3. Add some device kinds and actions to the grammar.
-
-
-
-#NEW
-
-==Proof objects==
-
-**Curry-Howard isomorphism** = **propositions as types principle**:
-a proposition is a type of proofs (= proof objects).
-
-Example: define the //less than// proposition for natural numbers,
-```
-  cat Nat ; 
-  fun Zero : Nat ;
-  fun Succ : Nat -> Nat ;
-```
-Define inductively what it means for a number //x// to be //less than//
-a number //y//:
-- ``Zero`` is less than ``Succ`` //y// for any //y//.
-- If //x// is less than //y//, then ``Succ`` //x// is less than ``Succ`` //y//.
-
-
-Expressing these axioms in type theory
-with a dependent type ``Less`` //x y// and two functions constructing
-its objects:
-```
-  cat Less Nat Nat ; 
-  fun lessZ : (y : Nat) -> Less Zero (Succ y) ;
-  fun lessS : (x,y : Nat) -> Less x y -> Less (Succ x) (Succ y) ;
-```
-Example: the fact that 2 is less that 4 has the proof object
-```
-  lessS (Succ Zero) (Succ (Succ (Succ Zero)))
-        (lessS Zero (Succ (Succ Zero)) (lessZ (Succ Zero)))
-   : Less (Succ (Succ Zero)) (Succ (Succ (Succ (Succ Zero))))
-```
-
-
-
-#NEW
-
-===Proof-carrying documents===
-
-Idea: to be semantically well-formed, the abstract syntax of a document 
-must contain a proof of some property, 
-although the proof is not shown in the concrete document.
-
-Example: documents describing flight connections:
-
-//To fly from Gothenburg to Prague, first take LH3043 to Frankfurt, then OK0537 to Prague.//
-
-The well-formedness of this text is partly expressible by dependent typing: 
-```
-  cat
-    City ;
-    Flight City City ;
-  fun
-    Gothenburg, Frankfurt, Prague : City ;
-    LH3043 : Flight Gothenburg Frankfurt ;
-    OK0537 : Flight Frankfurt Prague ;
-```
-To extend the conditions to flight connections, we introduce a category
-of proofs that a change is possible:
-```
-  cat IsPossible (x,y,z : City)(Flight x y)(Flight y z) ;
-```
-A legal connection is formed by the function
-```
-  fun Connect : (x,y,z : City) -> 
-    (u : Flight x y) -> (v : Flight y z) -> 
-      IsPossible x y z u v -> Flight x z ;
-```
-
-
-#NEW
-
-==Restricted polymorphism==
-
-Above, all Actions were either of
-- **monomorphic**: defined for one Kind
-- **polymorphic**: defined for all Kinds
-
-
-To make this scale up for new Kinds, we can refine this to 
-**restricted polymorphism**: defined for Kinds of a certain **class**
-
-
-The notion of class uses the Curry-Howard isomorphism as follows:
-- a class is a **predicate** of Kinds --- i.e. a type depending of Kinds
-- a Kind is in a class if there is a proof object of this type
-
-
-#NEW
-
-===Example: classes for switching and dimming===
-
-We modify the smart house grammar:
-```
-cat
-  Switchable Kind ;
-  Dimmable   Kind ;
-fun
-  switchable_light : Switchable light ;
-  switchable_fan   : Switchable fan ;
-  dimmable_light   : Dimmable light ;
-
-  switchOn : (k : Kind) -> Switchable k -> Action k ;
-  dim      : (k : Kind) -> Dimmable k -> Action k ;
-```
-Classes for new actions can be added incrementally. 
-
-
-
-#NEW
-
-==Variable bindings==
-
-#Lsecbinding
-
-Mathematical notation and programming languages have
-expressions that **bind** variables. 
-
-Example: universal quantifier formula
-```
-  (All x)B(x)
-```
-The variable ``x`` has a **binding** ``(All x)``, and
-occurs **bound** in the **body** ``B(x)``.
-
-Examples from informal mathematical language:
-```
-  for all x, x is equal to x
-
-  the function that for any numbers x and y returns the maximum of x+y
-  and x*y
-
-  Let x be a natural number. Assume that x is even. Then x + 3 is odd.
-```
-
-
-
-#NEW
-
-===Higher-order abstract syntax===
-
-Abstract syntax can use functions as arguments:
-```
-  cat Ind ; Prop ;
-  fun All : (Ind -> Prop) -> Prop
-```
-where ``Ind`` is the type of individuals and ``Prop``,
-the type of propositions. 
-
-Let us add an equality predicate
-```
-  fun Eq : Ind -> Ind -> Prop
-```
-Now we can form the tree
-```
-  All (\x -> Eq x x)
-```
-which we want to relate to the ordinary notation
-```
-  (All x)(x = x)
-```
-In **higher-order abstract syntax** (HOAS), all variable bindings are
-expressed using higher-order syntactic constructors.
-
-
-#NEW
-
-===Higher-order abstract syntax: linearization===
-
-HOAS has proved to be useful in the semantics and computer implementation of
-variable-binding expressions. 
-
-How do we relate HOAS to the concrete syntax?
-
-In GF, we write
-```
-  fun All : (Ind -> Prop) -> Prop
-  lin All B = {s = "(" ++ "All" ++ B.$0 ++ ")" ++ B.s}
-```
-General rule: if an argument type of a ``fun`` function is
-a function type ``A -> C``, the linearization type of
-this argument is the linearization type of ``C``
-together with a new field ``$0 : Str``. 
-
-The argument ``B`` thus has the linearization type
-```
-  {s : Str ; $0 : Str},
-```
-If there are more bindings, we add ``$1``, ``$2``, etc.
-
-
-#NEW
-
-===Eta expansion===
-
-To make sense of linearization, syntax trees must be
-**eta-expanded**: for any function of type
-```
-  A -> B
-```
-an eta-expanded syntax tree has the form
-```
-  \x -> b
-```
-where ``b : B`` under the assumption ``x : A``.
-
-Given the linearization rule
-```
-  lin Eq a b = {s = "(" ++ a.s ++ "=" ++ b.s ++ ")"}
-```
-the linearization of the tree 
-```
-  \x -> Eq x x
-```
-is the record
-```
-  {$0 = "x", s = ["( x = x )"]}
-```
-Then we can compute the linearization of the formula,
-```
-  All (\x -> Eq x x)  --> {s = "[( All x ) ( x = x )]"}.
-```
-The linearization of the variable ``x`` is, 
-"automagically", the string ``"x"``.
-
-
-
-#NEW
-
-===Parsing variable bindings===
-
-GF can treat any one-word string as a variable symbol.
-```
-  > p -cat=Prop "( All x ) ( x = x )"
-  All (\x -> Eq x x)
-```
-Variables must be bound if they are used:
-```
-  > p -cat=Prop "( All x ) ( x = y )"
-  no tree found
-```
-
-
-
-
-#NEW
-
-===Exercises on variable bindings===
-
-1. Write an abstract syntax of the whole
-**predicate calculus**, with the
-**connectives** "and", "or", "implies", and "not", and the
-**quantifiers** "exists" and "for all". Use higher-order functions
-to guarantee that unbounded variables do not occur.
-
-2. Write a concrete syntax for your favourite
-notation of predicate calculus. Use Latex as target language
-if you want nice output. You can also try producing boolean
-expressions of some programming language. Use as many parenthesis as you need to
-guarantee non-ambiguity.
-
-
-#NEW
-
-==Semantic definitions==
-
-#Lsecdefdef
-
-The ``fun`` judgements of GF are declarations of functions, giving their types.
-
-Can we **compute** ``fun`` functions?
-
-Mostly we are not interested, since functions are seen as constructors,
-i.e. data forms - as usual with
-```
-  fun Zero : Nat ;
-  fun Succ : Nat -> Nat ;
-```
-But it is also possible to give **semantic definitions** to functions.
-The key word is ``def``:
-```
-  fun one : Nat ;
-  def one = Succ Zero ;
-
-  fun twice : Nat -> Nat ;
-  def twice x = plus x x ;
-
-  fun plus : Nat -> Nat -> Nat ;
-  def 
-    plus x Zero = x ;
-    plus x (Succ y) = Succ (Sum x y) ;
-```
-
-#NEW
-
-===Computing a tree===
-
-Computation: follow a chain of definition until no definition
-can be applied,
-```
-  plus one one -->
-  plus (Succ Zero) (Succ Zero) -->
-  Succ (plus (Succ Zero) Zero) -->
-  Succ (Succ Zero)
-```
-Computation in GF is performed with the ``put_term`` command and the
-``compute`` transformation, e.g.
-```
-  > parse -tr "1 + 1" | put_term -transform=compute -tr | l
-  plus one one
-  Succ (Succ Zero)
-  s(s(0))
-```
-
-
-#NEW
-
-===Definitional equality===
-
-Two trees are definitionally equal if they compute into the same tree.
-
-Definitional equality does not guarantee sameness of linearization:
-```
-  plus one one     ===> 1 + 1
-  Succ (Succ Zero) ===> s(s(0))
-```
-The main use of this concept is in type checking: sameness of types.
-
-Thus e.g. the following types are equal
-```
-  Less Zero one
-  Less Zero (Succ Zero))
-```
-so that an object of one also is an object of the other.
-
-
-
-#NEW
-
-===Judgement forms for constructors===
-
-The judgement form ``data`` tells that a category has 
-certain functions as constructors:
-```
-  data Nat = Succ | Zero ;
-```
-The type signatures of constructors are given separately, 
-```
-  fun Zero : Nat ;
-  fun Succ : Nat -> Nat ;
-```
-There is also a shorthand:
-```
-  data Succ : Nat -> Nat ;    ===   fun Succ : Nat -> Nat ;
-                                    data Nat = Succ ;
-```
-Notice: in ``def`` definitions, identifier patterns not
-marked as ``data`` will be treated as variables.
-
-
-#NEW
-
-===Exercises on semantic definitions===
-
-1. Implement an interpreter of a small functional programming
-language with natural numbers, lists, pairs, lambdas, etc. Use higher-order
-abstract syntax with semantic definitions. As concrete syntax, use
-your favourite programming language.
-
-2. There is no termination checking for ``def`` definitions. 
-Construct an examples that makes type checking loop.
-Type checking can be invoked with ``put_term -transform=solve``.
-
-
-
-#NEW
-
-==Lesson 6: Grammars of formal languages==
-
-
-#Lchapseven
-
-Goals:
-- write grammars for formal languages (mathematical notation, programming languages)
-- interface between formal and natural langauges
-- implement a compiler by using GF
-
-
-#NEW
-
-===Arithmetic expressions===
-
-We construct a calculator with addition, subtraction, multiplication, and
-division of integers. 
-```
-  abstract Calculator = {
-
-  cat Exp ;
-
-  fun
-    EPlus, EMinus, ETimes, EDiv : Exp -> Exp -> Exp ;
-    EInt : Int -> Exp ;
-  }
-```
-The category ``Int`` is a built-in category of
-integers. Its syntax trees **integer literals**, i.e.
-sequences of digits:
-```
-  5457455814608954681 : Int
-```
-These are the only objects of type ``Int``:
-grammars are not allowed to declare functions with ``Int`` as value type.
-
-
-#NEW
-
-===Concrete syntax: a simple approach===
-
-We begin with a
-concrete syntax that always uses parentheses around binary
-operator applications: 
-```
-  concrete CalculatorP of Calculator = {
-
-  lincat 
-    Exp = SS ;
-  lin
-    EPlus  = infix "+" ;
-    EMinus = infix "-" ;
-    ETimes = infix "*" ;
-    EDiv   = infix "/" ;
-    EInt i = i ;
-
-  oper
-    infix : Str -> SS -> SS -> SS = \f,x,y -> 
-      ss ("(" ++ x.s ++ f ++ y.s ++ ")") ;
-  }
-```
-Now we have
-```
-  > linearize EPlus (EInt 2) (ETimes (EInt 3) (EInt 4))
-  ( 2 + ( 3 * 4 ) )
-```
-First problems: 
-- to get rid of superfluous spaces and 
-- to recognize integer literals in the parser
-
-
-#NEW
-
-==Lexing and unlexing==
-
-#Lseclexing
-
-The input of parsing in GF is not just a string, but a list of
-**tokens**, returned by a **lexer**.
-
-The default lexer in GF returns chunks separated by spaces:
-```
-  "(12 + (3 * 4))"  ===>  "(12", "+", "(3". "*". "4))"
-```
-The proper way would be
-```
-  "(", "12", "+", "(", "3", "*", "4", ")", ")"
-```
-Moreover, the tokens ``"12"``, ``"3"``, and ``"4"`` should be recognized as
-integer literals - they cannot be found in the grammar.
-
-
-#NEW
-
-Lexers are invoked by flags to the command ``put_string = ps``.
-```
-  > put_string -lexcode "(2 + (3 * 4))"
-  ( 2 + ( 3 * 4 ) )
-```
-This can be piped into a parser, as usual:
-```
-  > ps -lexcode "(2 + (3 * 4))" | parse
-  EPlus (EInt 2) (ETimes (EInt 3) (EInt 4))
-```
-In linearization, we use a corresponding **unlexer**:
-```
-  > linearize EPlus (EInt 2) (ETimes (EInt 3) (EInt 4)) | ps -unlexcode
-  (2 + (3 * 4))
-```
-
-
-#NEW
-
-===Most common lexers and unlexers===
-
-  || lexer       | unlexer        | description ||
-  | ``chars``    | ``unchars``    | each character is a token
-  | ``lexcode``  | ``unlexcode``  | program code conventions (uses Haskell's lex)
-  | ``lexmixed`` | ``unlexmixed`` | like text, but between $ signs like code
-  | ``lextext``  | ``unlextext``  | with conventions on punctuation and capitals
-  | ``words``    | ``unwords``    | (default) tokens separated by space characters 
-
-%TODO: also on alphabet encodings - although somewhere else
-
-
-#NEW
-
-==Precedence and fixity==
-
-Arithmetic expressions should be unambiguous. If we write
-```
-  2 + 3 * 4
-```
-it should be parsed as one, but not both, of
-```
-  EPlus (EInt 2) (ETimes (EInt 3) (EInt 4))
-  ETimes (EPlus (EInt 2) (EInt 3)) (EInt 4)
-```
-We choose the former tree, because
-multiplication has **higher precedence** than addition.
-
-To express the latter tree, we have to use parentheses:
-```
-  (2 + 3) * 4
-```
-The usual precedence rules:
-- Integer constants and expressions in parentheses have the highest precedence.
-- Multiplication and division have equal precedence, lower than the highest
-  but higher than addition and subtraction, which are again equal.
-- All the four binary operations are **left-associative**:
-  ``1 + 2 + 3`` means the same as ``(1 + 2) + 3``.
-
-
-
-#NEW
-
-===Precedence as a parameter===
-
-Precedence can be made into an inherent feature of expressions:
-```
-  oper
-    Prec : PType = Ints 2 ;
-    TermPrec : Type = {s : Str ; p : Prec} ;
-
-    mkPrec : Prec -> Str -> TermPrec = \p,s -> {s = s ; p = p} ;
-
-  lincat 
-    Exp = TermPrec ;
-```
-Notice ``Ints 2``: a parameter type, whose values are the integers
-``0,1,2``. 
-
-Using precedence levels: compare the inherent precedence of an 
-expression with the expected precedence.
-- if the inherent precedence is lower than the expected precedence,
-  use parentheses
-- otherwise, no parentheses are needed
-
-
-This idea is encoded in the operation
-```
-  oper usePrec : TermPrec -> Prec -> Str = \x,p ->
-    case lessPrec x.p p of {
-      True  => "(" x.s ")" ;
-      False => x.s
-    } ;
-```
-(We use ``lessPrec`` from ``lib/prelude/Formal``.)
-
-
-
-#NEW
-
-===Fixities===
-
-We can define left-associative infix expressions:
-```
-  infixl : Prec -> Str -> (_,_ : TermPrec) -> TermPrec = \p,f,x,y ->
-    mkPrec p (usePrec x p ++ f ++ usePrec y (nextPrec p)) ;
-```
-Constant-like expressions (the highest level):
-```
-  constant : Str -> TermPrec = mkPrec 2 ;
-```
-All these operations can be found in ``lib/prelude/Formal``,
-which has 5 levels.
-
-Now we can write the whole concrete syntax of ``Calculator`` compactly:
-```
-  concrete CalculatorC of Calculator = open Formal, Prelude in {
-
-  flags lexer = codelit ; unlexer = code ; startcat = Exp ;
-
-  lincat Exp = TermPrec ;
-
-  lin
-    EPlus  = infixl 0 "+" ;
-    EMinus = infixl 0 "-" ;
-    ETimes = infixl 1 "*" ;
-    EDiv   = infixl 1 "/" ;
-    EInt i = constant i.s ;
-  }
-```
-
-
-#NEW
-
-===Exercises on precedence===
-
-1. Define non-associative and right-associative infix operations
-analogous to ``infixl``.
-
-2. Add a constructor that puts parentheses around expressions
-to raise their precedence, but that is eliminated by a ``def`` definition.
-Test parsing with and without a pipe to ``pt -transform=compute``.
-
-
-
-#NEW
-
-==Code generation as linearization==
-
-Translate arithmetic (infix) to JVM (postfix):
-```
-  2 + 3 * 4
-
-    ===>
-
-  iconst 2 : iconst 3 ; iconst 4 ; imul ; iadd
-```
-Just give linearization rules for JVM:
-```
-  lin
-    EPlus  = postfix "iadd" ;
-    EMinus = postfix "isub" ;
-    ETimes = postfix "imul" ;
-    EDiv   = postfix "idiv" ;
-    EInt i = ss ("iconst" ++ i.s) ;
-  oper
-    postfix : Str -> SS -> SS -> SS = \op,x,y -> 
-      ss (x.s ++ ";" ++ y.s ++ ";" ++ op) ;
-```
-
-
-#NEW
-
-===Programs with variables===
-
-A **straight code** programming language, with
-**initializations** and **assignments**:
-```
-  int x = 2 + 3 ;  
-  int y = x + 1 ; 
-  x = x + 9 * y ;
-```
-We define programs by the following constructors:
-```
-  fun
-    PEmpty : Prog ;
-    PInit  : Exp -> (Var -> Prog) -> Prog ;
-    PAss   : Var -> Exp  -> Prog  -> Prog ;
-```
-``PInit`` uses higher-order abstract syntax for making the 
-initialized variable available in the **continuation** of the program. 
-
-The abstract syntax tree for the above code is
-```
-  PInit (EPlus (EInt 2) (EInt 3)) (\x -> 
-    PInit (EPlus (EVar x) (EInt 1)) (\y -> 
-      PAss x (EPlus (EVar x) (ETimes (EInt 9) (EVar y))) 
-        PEmpty))
-```
-No uninitialized variables are allowed - there are no constructors for ``Var``! 
-But we do have the rule
-```
-  fun EVar : Var -> Exp ;
-```
-The rest of the grammar is just the same as for arithmetic expressions
-#Rsecprecedence. The best way to implement it is perhaps by writing a
-module that extends the expression module. The most natural start category
-of the extension is ``Prog``.
-
-
-#NEW
-
-===Exercises on code generation===
-
-1. Define a C-like concrete syntax of the straight-code language.
-
-2. Extend the straight-code language to expressions of type ``float``.
-To guarantee type safety, you can define a category ``Typ`` of types, and
-make ``Exp`` and ``Var`` dependent on ``Typ``. Basic floating point expressions
-can be formed from literal of the built-in GF type ``Float``. The arithmetic
-operations should be made polymorphic (as #Rsecpolymorphic).
-
-3. Extend JVM generation to the straight-code language, using
-two more instructions
-- ``iload`` //x//, which loads the value of the variable //x//
-- ``istore`` //x// which stores a value to the variable //x//
-
-
-Thus the code for the example in the previous section is
-```
-  iconst 2 ; iconst 3 ; iadd ; istore x ;
-  iload x ; iconst 1 ; iadd ; istore y ;
-  iload x ; iconst 9 ; iload y ; imul ; iadd ; istore x ;
-```
-
-4. If you made the exercise of adding floating point numbers to
-the language, you can now cash out the main advantage of type checking
-for code generation: selecting type-correct JVM instructions. The floating
-point instructions are precisely the same as the integer one, except that
-the prefix is ``f`` instead of ``i``, and that ``fconst`` takes floating
-point literals as arguments.
-
-
-
-#NEW
-
-=Lesson 7: Embedded grammars=
-
-#Lchapeight
-
-Goals:
-- use grammars as parts of programs written in Haskell and JavaScript
-- implement stand-alone question-answering systems and translators based on
-  GF grammars
-- generate language models for speech recognition from GF grammars
-
-
- 
-#NEW
-
-==Functionalities of an embedded grammar format==
-
-GF grammars can be used as parts of programs written in other programming
-languages, to be called **host languages**.
-This facility is based on several components:
-- PGF: a portable format for multilingual GF grammars
-- a PGF interpreter written in the host language
-- a library in the host language that enables calling the interpreter
-- a way to manipulate abstract syntax trees in the host language
-
-
-
-
-#NEW
-
-==The portable grammar format==
-
-The portable format is called PGF, "Portable Grammar Format".
-
-This format is produced by the GF batch compiler ``gfc``, 
-executable from the operative system shell:
-```
-  % gfc --make SOURCE.gf
-```
-PGF is the recommended format in 
-which final grammar products are distributed, because they
-are stripped from superfluous information and can be started and applied
-faster than sets of separate modules.
-
-Application programmers have never any need to read or modify PGF files. 
-
-PGF thus plays the same role as machine code in 
-general-purpose programming (or bytecode in Java).
-
-
-#NEW
-
-===Haskell: the EmbedAPI module===
-
-The Haskell API contains (among other things) the following types and functions:
-```
-  readPGF   :: FilePath -> IO PGF
-
-  linearize :: PGF -> Language -> Tree -> String
-  parse     :: PGF -> Language -> Category -> String -> [Tree]
-
-  linearizeAll     :: PGF -> Tree -> [String]
-  linearizeAllLang :: PGF -> Tree -> [(Language,String)]
-
-  parseAll     :: PGF -> Category -> String -> [[Tree]]
-  parseAllLang :: PGF -> Category -> String -> [(Language,[Tree])]
-
-  languages    :: PGF -> [Language]
-  categories   :: PGF -> [Category]
-  startCat     :: PGF -> Category
-```
-This is the only module that needs to be imported in the Haskell application.
-It is available as a part of the GF distribution, in the file
-``src/PGF.hs``.
-
-
-
-#NEW
-
-===First application: a translator===
-
-Let us first build a stand-alone translator, which can translate
-in any multilingual grammar between any languages in the grammar.
-```
-module Main where
-
-import PGF
-import System (getArgs)
-
-main :: IO () 
-main = do
-  file:_ <- getArgs
-  gr     <- readPGF file
-  interact (translate gr)
-
-translate :: PGF -> String -> String
-translate gr s = case parseAllLang gr (startCat gr) s of
-  (lg,t:_):_ -> unlines [linearize gr l t | l <- languages gr, l /= lg]
-  _ -> "NO PARSE"
-```
-To run the translator, first compile it by
-```
-  % ghc --make -o trans Translator.hs 
-```
-For this, you need the Haskell compiler [GHC http://www.haskell.org/ghc].
-
-
-#NEW
-
-===Producing GFCC for the translator===
-
-Then produce a GFCC file. For instance, the ``Food`` grammar set can be 
-compiled as follows:
-```
-  % gfc --make FoodEng.gf FoodIta.gf
-```
-This produces the file ``Food.pgf`` (its name comes from the abstract syntax).
-
-The Haskell library function ``interact`` makes the ``trans`` program work
-like a Unix filter, which reads from standard input and writes to standard
-output. Therefore it can be a part of a pipe and read and write files.
-The simplest way to translate is to ``echo`` input to the program:
-```
-  % echo "this wine is delicious" | ./trans Food.pgf
-  questo vino è delizioso
-```
-The result is given in all languages except the input language.
-
-%TODO convert the output to UTF8
-
-
-#NEW
-
-===A translator loop===
-
-To avoid starting the translator over and over again:
-change ``interact`` in the main function to ``loop``, defined as
-follows:
-```
-loop :: (String -> String) -> IO ()
-loop trans = do 
-  s <- getLine
-  if s == "quit" then putStrLn "bye" else do  
-    putStrLn $ trans s
-    loop trans
-```
-The loop keeps on translating line by line until the input line
-is ``quit``.
-
-
-
-#NEW
-
-===A question-answer system===
-
-#Lsecmathprogram
-
-The next application is also a translator, but it adds a
-**transfer** component - a function that transforms syntax trees.
-
-The transfer function we use is one that computes a question into an answer.
-
-The program accepts simple questions about arithmetic and answers
-"yes" or "no" in the language in which the question was made:
-```
-  Is 123 prime?
-  No.
-  77 est impair ?
-  Oui.
-```
-We change the pure translator by giving
-the ``translate`` function the transfer as an extra argument:
-```
-  translate :: (Tree -> Tree) -> PGF -> String -> String
-```
-Ordinary translation as a special case where
-transfer is the identity function (``id`` in Haskell).
-
-To reply in the //same// language as the question:
-```
-  translate tr gr = case parseAllLang gr (startCat gr) s of
-    (lg,t:_):_ -> linearize gr lg (tr t)
-    _ -> "NO PARSE"
-```
-
-
-#NEW
-
-===Abstract syntax of the query system===
-
-Input: abstract syntax judgements
-```
-abstract Query = {
-
-  flags startcat=Question ;
-
-  cat 
-    Answer ; Question ; Object ;
-
-  fun 
-    Even   : Object -> Question ;
-    Odd    : Object -> Question ;
-    Prime  : Object -> Question ;
-    Number : Int -> Object ;
-
-    Yes : Answer ;
-    No  : Answer ;
-}
-```
-
-
-#NEW
-
-===Exporting GF datatypes to Haskell===
-
-To make it easy to define a transfer function, we export the
-abstract syntax to a system of Haskell datatypes:
-```
-  % gfc --output-format=haskell Query.pgf
-```
-It is also possible to produce the Haskell file together with GFCC, by
-```
-  % gfc --make --output-format=haskell QueryEng.gf
-```
-The result is a file named ``Query.hs``, containing a 
-module named ``Query``. 
-
-
-#NEW
-
-Output: Haskell definitions
-```
-module Query where
-import PGF
-
-data GAnswer =
-   GYes 
- | GNo 
-
-data GObject = GNumber GInt 
-
-data GQuestion =
-   GPrime GObject 
- | GOdd GObject 
- | GEven GObject 
-
-newtype GInt = GInt Integer
-```
-All type and constructor names are prefixed with a ``G`` to prevent clashes.
-
-The Haskell module name is the same as the abstract syntax name.
-
-
-#NEW
-
-===The question-answer function===
-
-Haskell's type checker guarantees that the functions are well-typed also with
-respect to GF. 
-```
-answer :: GQuestion -> GAnswer
-answer p = case p of
-  GOdd x   -> test odd x
-  GEven x  -> test even x
-  GPrime x -> test prime x
-
-value :: GObject -> Int
-value e = case e of
-  GNumber (GInt i) -> fromInteger i
-
-test :: (Int -> Bool) -> GObject -> GAnswer
-test f x = if f (value x) then GYes else GNo
-```
-
-
-#NEW
-
-===Converting between Haskell and GF trees===
-
-The generated Haskell module also contains
-```
-class Gf a where 
-  gf :: a -> Tree
-  fg :: Tree -> a
-
-instance Gf GQuestion where
-  gf (GEven x1) = DTr [] (AC (CId "Even")) [gf x1]
-  gf (GOdd x1) = DTr [] (AC (CId "Odd")) [gf x1]
-  gf (GPrime x1) = DTr [] (AC (CId "Prime")) [gf x1]
-  fg t =
-    case t of
-      DTr [] (AC (CId "Even")) [x1] -> GEven (fg x1)
-      DTr [] (AC (CId "Odd")) [x1] -> GOdd (fg x1)
-      DTr [] (AC (CId "Prime")) [x1] -> GPrime (fg x1)
-      _ -> error ("no Question " ++ show t)
-```
-For the programmer, it is enougo to know:
-- all GF names are in Haskell prefixed with ``G``
-- ``gf`` translates from Haskell objects to GF trees
-- ``fg`` translates from GF trees to Haskell objects
-
-
-
-#NEW
-
-===Putting it all together: the transfer definition===
-
-```
-module TransferDef where
-
-import PGF (Tree)
-import Query   -- generated from GF
-
-transfer :: Tree -> Tree
-transfer = gf . answer . fg
-
-answer :: GQuestion -> GAnswer
-answer p = case p of
-  GOdd x   -> test odd x
-  GEven x  -> test even x
-  GPrime x -> test prime x
-
-value :: GObject -> Int
-value e = case e of
-  GNumber (GInt i) -> fromInteger i
-
-test :: (Int -> Bool) -> GObject -> GAnswer
-test f x = if f (value x) then GYes else GNo
-
-prime :: Int -> Bool
-prime x = elem x primes where
-  primes = sieve [2 .. x]
-  sieve (p:xs) = p : sieve [ n | n <- xs, n `mod` p > 0 ]
-  sieve [] = []
-```
-
-
-#NEW
-
-===Putting it all together: the Main module===
-
-Here is the complete code in the Haskell file ``TransferLoop.hs``.
-```
-module Main where
-
-import PGF
-import TransferDef (transfer)
-
-main :: IO () 
-main = do
-  gr <- readPGF "Query.pgf"
-  loop (translate transfer gr)
-
-loop :: (String -> String) -> IO ()
-loop trans = do 
-  s <- getLine
-  if s == "quit" then putStrLn "bye" else do  
-    putStrLn $ trans s
-    loop trans
-
-translate :: (Tree -> Tree) -> PGF -> String -> String
-translate tr gr s = case parseAllLang gr (startCat gr) s of
-  (lg,t:_):_ -> linearize gr lg (tr t)
-  _ -> "NO PARSE"
-```
-
-
-
-#NEW
-
-===Putting it all together: the Makefile===
-
-To automate the production of the system, we write a ``Makefile`` as follows:
-```
-all:
-        gfc --make --output-format=haskell QueryEng
-        ghc --make -o ./math TransferLoop.hs
-        strip math
-```
-(The empty segments starting the command lines in a Makefile must be tabs.)
-Now we can compile the whole system by just typing 
-```
-  make
-```
-Then you can run it by typing
-```
-  ./math
-```
-Just to summarize, the source of the application consists of the following files:
-```
-  Makefile         -- a makefile
-  Math.gf          -- abstract syntax
-  Math???.gf       -- concrete syntaxes
-  TransferDef.hs   -- definition of question-to-answer function
-  TransferLoop.hs  -- Haskell Main module
-```
-
-#NEW
-
-==Web server applications==
-
-PGF files can be used in web servers, for which there is a Haskell library included
-in ``src/server/``. How to build a server for tasks like translators is explained 
-in the [``README`` ../src/server/README] file in that directory. 
-
-One of the servers that can be readily built with the library (without any
-programming required) is **fridge poetry magnets**. It is an application that
-uses an incremental parser to suggest grammatically correct next words. Here
-is an example of its application to the ``Foods`` grammars.
-
-[food-magnet.png]
-
-
-#NEW
-
-==JavaScript applications==
-
-JavaScript is a programming language that has interpreters built in in most
-web browsers. It is therefore usable for client side web programs, which can even
-be run without access to the internet. The following figure shows a JavaScript
-program compiled from GF grammars as run on an iPhone.
-
-[iphone.jpg]
-
-
-#NEW
-
-===Compiling to JavaScript===
-
-JavaScript is one of the output formats of the GF batch compiler. Thus the following
-command generates a JavaScript file from two ``Food`` grammars.
-```
-  % gfc --make --output-format=js FoodEng.gf FoodIta.gf
-```
-The name of the generated file is ``Food.js``, derived from the top-most abstract
-syntax name. This file contains the multilingual grammar as a JavaScript object.
-
-
-#NEW
-
-===Using the JavaScript grammar===
-
-To perform parsing and linearization, the run-time library
-``gflib.js`` is used. It is included in ``GF/lib/javascript/``, together with
-some other JavaScript and HTML files; these files can be used 
-as templates for building applications.
-
-An example of usage is 
-[``translator.html`` ../lib/javascript/translator.html], 
-which is in fact initialized with
-a pointer to the Food grammar, so that it provides translation between the English
-and Italian grammars:
-
-[food-js.png]
-
-The grammar must have the name ``grammar.js``. The abstract syntax and start 
-category names in ``translator.html`` must match the ones in the grammar.
-With these changes, the translator works for any multilingual grammar.
-
-
-
-
-
-#NEW
-
-==Language models for speech recognition==
-
-The standard way of using GF in speech recognition is by building
-**grammar-based language models**. 
-
-GF supports several formats, including
-GSL, the formatused in the [Nuance speech recognizer www.nuance.com].
-
-GSL is produced from GF by running ``gfc`` with the flag
-``--output-format=gsl``. 
-
-Example: GSL  generated from ``FoodsEng.gf``.
-```
-  % gfc --make --output-format=gsl FoodsEng.gf
-  % more FoodsEng.gsl
-
-  ;GSL2.0
-  ; Nuance speech recognition grammar for FoodsEng
-  ; Generated by GF
-
-  .MAIN Phrase_cat
-
-  Item_1 [("that" Kind_1) ("this" Kind_1)]
-  Item_2 [("these" Kind_2) ("those" Kind_2)]
-  Item_cat [Item_1 Item_2]
-  Kind_1 ["cheese" "fish" "pizza" (Quality_1 Kind_1)
-          "wine"]
-  Kind_2 ["cheeses" "fish" "pizzas"
-          (Quality_1 Kind_2) "wines"]
-  Kind_cat [Kind_1 Kind_2]
-  Phrase_1 [(Item_1 "is" Quality_1)
-            (Item_2 "are" Quality_1)]
-  Phrase_cat Phrase_1
-  
-  Quality_1 ["boring" "delicious" "expensive"
-             "fresh" "italian" ("very" Quality_1) "warm"]
-  Quality_cat Quality_1
-```
-
-
-#NEW
-
-===More speech recognition grammar formats===
-
-Other formats available via the ``--output-format`` flag include:
-
-    || Format            | Description ||
-    | ``gsl``            | Nuance GSL speech recognition grammar
-    | ``jsgf``           | Java Speech Grammar Format (JSGF)
-    | ``jsgf_sisr_old``  | JSGF with semantic tags in SISR  WD 20030401 format
-    | ``srgs_abnf``      | SRGS ABNF format
-    | ``srgs_xml``       | SRGS XML format
-    | ``srgs_xml_prob``  | SRGS XML format, with weights
-    | ``slf``            | finite automaton in the HTK SLF format
-    | ``slf_sub``        | finite automaton with sub-automata in HTK SLF
-
-All currently available formats can be seen with ``gfc --help``.
-
-