--- a/doc-src/TutorialI/Trie/document/Trie.tex Wed Jan 24 11:59:15 2001 +0100
+++ b/doc-src/TutorialI/Trie/document/Trie.tex Wed Jan 24 12:29:10 2001 +0100
@@ -120,7 +120,7 @@
This proof may look surprisingly straightforward. However, note that this
comes at a cost: the proof script is unreadable because the intermediate
proof states are invisible, and we rely on the (possibly brittle) magic of
-\isa{auto} (\isa{simp{\isacharunderscore}all} will not do---try it) to split the subgoals
+\isa{auto} (\isa{simp{\isacharunderscore}all} will not do --- try it) to split the subgoals
of the induction up in such a way that case distinction on \isa{bs} makes
sense and solves the proof. Part~\ref{Isar} shows you how to write readable
and stable proofs.%