started a subdir for the book

1 files changed, 28 insertions, 0 deletions

diff --git a/book/examples/chapter6/Classes.gf b/book/examples/chapter6/Classes.gf
new file mode 100644
index 000000000..ac7430d25
--- /dev/null
+++ b/book/examples/chapter6/Classes.gf
@@ -0,0 +1,28 @@
+abstract Classes = {
+
+flags 
+  startcat = Command ;
+
+cat
+  Command ;
+  Kind ;
+  Class ;
+  Instance Class Kind ;
+  Action Class ;
+  Device Kind ;
+
+fun
+  Act  : (c : Class) -> (k : Kind) -> Instance c k -> Action c -> Device k -> Command ;
+  The : (k : Kind) -> Device k ;
+
+  Light, Fan : Kind ;
+  Switchable, Dimmable : Class ;
+  
+  SwitchOn, SwitchOff : Action Switchable ;
+  Dim : Action Dimmable ;
+
+  switchable_Light : Instance Switchable Light ;
+  switchable_Fan : Instance Switchable Fan ;
+  dimmable_Light : Instance Dimmable Light ;
+
+}