--- a/doc-src/TutorialI/CTL/CTLind.thy Tue Oct 17 22:25:23 2000 +0200
+++ b/doc-src/TutorialI/CTL/CTLind.thy Wed Oct 18 12:30:59 2000 +0200
@@ -16,7 +16,7 @@
then @{prop"s \<in> lfp(af A)"}. We prove this by inductively defining the set
@{term"Avoid s A"} of states reachable from @{term s} by a finite @{term
A}-avoiding path:
-% Second proof of opposite direction, directly by wellfounded induction
+% Second proof of opposite direction, directly by well-founded induction
% on the initial segment of M that avoids A.
*}
@@ -66,14 +66,14 @@
"\<forall>p\<in>Paths s. \<exists>i. p i \<in> A \<Longrightarrow> t \<in> Avoid s A \<longrightarrow> t \<in> lfp(af A)";
txt{*\noindent
The trick is not to induct on @{prop"t \<in> Avoid s A"}, as already the base
-case would be a problem, but to proceed by wellfounded induction @{term
+case would be a problem, but to proceed by well-founded induction @{term
t}. Hence @{prop"t \<in> Avoid s A"} needs to be brought into the conclusion as
well, which the directive @{text rule_format} undoes at the end (see below).
-But induction with respect to which wellfounded relation? The restriction
+But induction with respect to which well-founded relation? The restriction
of @{term M} to @{term"Avoid s A"}:
@{term[display]"{(y,x). (x,y) \<in> M \<and> x \<in> Avoid s A \<and> y \<in> Avoid s A \<and> x \<notin> A}"}
As we shall see in a moment, the absence of infinite @{term A}-avoiding paths
-starting from @{term s} implies wellfoundedness of this relation. For the
+starting from @{term s} implies well-foundedness of this relation. For the
moment we assume this and proceed with the induction:
*}
@@ -100,8 +100,8 @@
txt{*
Having proved the main goal we return to the proof obligation that the above
-relation is indeed wellfounded. This is proved by contraposition: we assume
-the relation is not wellfounded. Thus there exists an infinite @{term
+relation is indeed well-founded. This is proved by contraposition: we assume
+the relation is not well-founded. Thus there exists an infinite @{term
A}-avoiding path all in @{term"Avoid s A"}, by theorem
@{thm[source]wf_iff_no_infinite_down_chain}:
@{thm[display]wf_iff_no_infinite_down_chain[no_vars]}