# HG changeset patch # User wenzelm # Date 1130414346 -7200 # Node ID 71f250e05e057458c19dce518e922a257df8f3c5 # Parent 8b9c6af78a675f4e0537e1db95b48952d69c37e7 * HOL: alternative iff syntax; diff -r 8b9c6af78a67 -r 71f250e05e05 NEWS --- a/NEWS Thu Oct 27 13:54:43 2005 +0200 +++ b/NEWS Thu Oct 27 13:59:06 2005 +0200 @@ -57,6 +57,10 @@ *** HOL *** +* Alternative iff syntax "A <-> B" for equality on bool (with priority +25 like -->); output depends on the "iff" print_mode, the default is +"A = B" (with priority 50). + * In the context of the assumption "~(s = t)" the Simplifier rewrites "t = s" to False (by simproc "neq_simproc"). For backward compatibility this can be disabled by ML "reset use_neq_simproc".