1 files changed, 0 insertions, 4 deletions
diff --git a/library/set/regularity.tex b/library/set/regularity.tex
index 068d6a8..10f4a1f 100644
--- a/library/set/regularity.tex
+++ b/library/set/regularity.tex
@@ -59,10 +59,6 @@
     Straightforward.
 \end{proof}
 
-\begin{proposition}\label{in_implies_neq}
-    If $a\in A$, then $a\neq A$.
-\end{proposition}
-
 \begin{proposition}\label{in_asymmetric}
     For all sets $a, b$ such that $a\in b$ we have $b\notin a$.
 \end{proposition}