--- a/doc-src/TutorialI/Recdef/termination.thy Thu Oct 28 19:40:22 2004 +0200
+++ b/doc-src/TutorialI/Recdef/termination.thy Fri Oct 29 15:16:02 2004 +0200
@@ -28,11 +28,10 @@
@{text[display]"length (filter ... xs) < Suc (length xs)"}
We can either prove this as a separate lemma, or try to figure out which
existing lemmas may help. We opt for the second alternative. The theory of
-lists contains the simplification rule @{thm length_filter[no_vars]},
-which is already
-close to what we need, except that we still need to turn \mbox{@{text"< Suc"}}
+lists contains the simplification rule @{thm length_filter_le[no_vars]},
+which is what we need, provided we turn \mbox{@{text"< Suc"}}
into
-@{text"\<le>"} for the simplification rule to apply. Lemma
+@{text"\<le>"} so that the rule applies. Lemma
@{thm[source]less_Suc_eq_le} does just that: @{thm less_Suc_eq_le[no_vars]}.
Now we retry the above definition but supply the lemma(s) just found (or