# HG changeset patch # User nipkow # Date 1691562264 -7200 # Node ID 10264fe8012f3825418f434afb025b9888a422be # Parent 1e80fc36776c1a7f492994712e247ded7f65f7eb tuned diff -r 1e80fc36776c -r 10264fe8012f src/Doc/Prog_Prove/Logic.thy --- a/src/Doc/Prog_Prove/Logic.thy Tue Aug 08 23:55:33 2023 +0200 +++ b/src/Doc/Prog_Prove/Logic.thy Wed Aug 09 08:24:24 2023 +0200 @@ -841,7 +841,7 @@ \] as two inductive predicates. If you think of \a\ and \b\ as ``\(\'' and ``\)\'', -the grammar defines strings of balanced parentheses. +the grammars define balanced strings of parentheses. Prove \<^prop>\T w \ S w\ and \mbox{\<^prop>\S w \ T w\} separately and conclude \<^prop>\S w = T w\. \end{exercise}