| changeset 18576 | 8d98b7711e47 |
| parent 18447 | da548623916a |
| child 20503 | 503ac4c5ef91 |
--- a/src/HOL/Library/Nested_Environment.thy Wed Jan 04 17:04:11 2006 +0100 +++ b/src/HOL/Library/Nested_Environment.thy Wed Jan 04 19:22:53 2006 +0100 @@ -193,7 +193,7 @@ from prems have "lookup env (xs @ ys) \<noteq> None" by simp then have "lookup env xs \<noteq> None" by (rule contrapos_nn) (simp only: lookup_append_none) - then show ?thesis by (simp add: not_None_eq) + then show ?thesis by (simp) qed text {*