IOA/meta_theory/Option.ML
author clasohm
Wed, 02 Nov 1994 11:50:09 +0100
changeset 156 fd1be45b64bf
child 168 44ff2275d44f
permissions -rw-r--r--
added IOA to isabelle/HOL

val option_rws = Let_def :: Option.option.simps;
val SS = arith_ss addsimps option_rws;

val [prem] = goal Option.thy "P(opt) ==> P(None) | (? x. P(Some(x)))";
 br (prem RS rev_mp) 1;
 by (Option.option.induct_tac "opt" 1);
 by (ALLGOALS(fast_tac HOL_cs));
val optE = standard(result() RS disjE);