1.1 --- a/doc-src/TutorialI/Recdef/Induction.thy Fri Jan 05 18:32:33 2001 +0100
1.2 +++ b/doc-src/TutorialI/Recdef/Induction.thy Fri Jan 05 18:32:57 2001 +0100
1.3 @@ -16,14 +16,15 @@
1.4 requires you to prove for each \isacommand{recdef} equation that the property
1.5 you are trying to establish holds for the left-hand side provided it holds
1.6 for all recursive calls on the right-hand side. Here is a simple example
1.7 +involving the predefined @{term"map"} functional on lists:
1.8 *}
1.9
1.10 lemma "map f (sep(x,xs)) = sep(f x, map f xs)";
1.11
1.12 txt{*\noindent
1.13 -involving the predefined @{term"map"} functional on lists: @{term"map f xs"}
1.14 +Note that @{term"map f xs"}
1.15 is the result of applying @{term"f"} to all elements of @{term"xs"}. We prove
1.16 -this lemma by recursion induction w.r.t. @{term"sep"}:
1.17 +this lemma by recursion induction over @{term"sep"}:
1.18 *}
1.19
1.20 apply(induct_tac x xs rule: sep.induct);
1.21 @@ -46,7 +47,7 @@
1.22
1.23 In general, the format of invoking recursion induction is
1.24 \begin{quote}
1.25 -\isacommand{apply}@{text"(induct_tac ("}$x@1 \dots x@n$ @{text"rule:"} $f$@{text".induct)"}
1.26 +\isacommand{apply}@{text"(induct_tac "}$x@1 \dots x@n$ @{text"rule:"} $f$@{text".induct)"}
1.27 \end{quote}\index{*induct_tac}%
1.28 where $x@1~\dots~x@n$ is a list of free variables in the subgoal and $f$ the
1.29 name of a function that takes an $n$-tuple. Usually the subgoal will