Modified some defs and shortened proofs.
(* Title: HOL/ex/sorting.ML
ID: $Id$
Author: Tobias Nipkow
Copyright 1994 TU Muenchen
Some general lemmas
*)
goal Sorting.thy "!x.mset (xs@ys) x = mset xs x + mset ys x";
by (list.induct_tac "xs" 1);
by (ALLGOALS(asm_simp_tac (!simpset setloop (split_tac [expand_if]))));
qed "mset_append";
goal Sorting.thy "!x. mset [x:xs. ~p(x)] x + mset [x:xs.p(x)] x = \
\ mset xs x";
by (list.induct_tac "xs" 1);
by (ALLGOALS(asm_simp_tac (!simpset setloop (split_tac [expand_if]))));
qed "mset_compl_add";
Addsimps [mset_append, mset_compl_add];
goal Sorting.thy "set_of_list xs = {x.mset xs x ~= 0}";
by (list.induct_tac "xs" 1);
by (ALLGOALS(asm_simp_tac (!simpset setloop (split_tac [expand_if]))));
by (Fast_tac 1);
qed "set_of_list_via_mset";
(* Equivalence of two definitions of `sorted' *)
val prems = goalw Sorting.thy [transf_def]
"transf(le) ==> sorted1 le xs = sorted le xs";
by (list.induct_tac "xs" 1);
by (ALLGOALS(asm_simp_tac (!simpset setloop (split_tac [expand_list_case]))));
by (cut_facts_tac prems 1);
by (Fast_tac 1);
qed "sorted1_is_sorted";