--- a/List.ML Fri Feb 03 16:21:45 1995 +0100
+++ b/List.ML Wed Feb 08 11:34:11 1995 +0100
@@ -55,6 +55,12 @@
by(ALLGOALS(asm_simp_tac list_ss));
qed "append_is_Nil";
+goal List.thy "(xs @ ys = xs @ zs) = (ys=zs)";
+by (list.induct_tac "xs" 1);
+by(ALLGOALS(asm_simp_tac list_ss));
+qed "same_append_eq";
+
+
(** mem **)
goal List.thy "x mem (xs@ys) = (x mem xs | x mem ys)";
@@ -96,6 +102,13 @@
by(fast_tac HOL_cs 1);
qed "expand_list_case";
+goal List.thy "(xs=[] --> P([])) & (!y ys. xs=y#ys --> P(y#ys)) --> P(xs)";
+by(list.induct_tac "xs" 1);
+by(fast_tac HOL_cs 1);
+by(fast_tac HOL_cs 1);
+bind_thm("list_eq_cases",
+ impI RSN (2,allI RSN (2,allI RSN (2,impI RS (conjI RS (result() RS mp))))));
+
(** nth **)
val [nth_0,nth_Suc] = nat_recs nth_def;
@@ -120,7 +133,7 @@
qed "map_compose";
val list_ss = list_ss addsimps
- [not_Cons_self, append_assoc, append_Nil2, append_is_Nil,
+ [not_Cons_self, append_assoc, append_Nil2, append_is_Nil, same_append_eq,
mem_append, mem_filter,
map_ident, map_append, map_compose,
list_all_True, list_all_conj, nth_0, nth_Suc];