diff -r 6584901d694c -r b7443e5a5335 doc-src/TutorialI/Misc/AdvancedInd.thy --- a/doc-src/TutorialI/Misc/AdvancedInd.thy Mon Jun 23 15:26:48 2008 +0200 +++ b/doc-src/TutorialI/Misc/AdvancedInd.thy Mon Jun 23 15:26:49 2008 +0200 @@ -227,12 +227,7 @@ \begin{quote} \isacommand{apply}@{text"(induct_tac"} $y@1 \dots y@n$ @{text"rule:"} $r$@{text")"} \end{quote} -where $y@1, \dots, y@n$ are variables in the first subgoal. -The conclusion of $r$ can even be an (iterated) conjunction of formulae of -the above form in which case the application is -\begin{quote} -\isacommand{apply}@{text"(induct_tac"} $y@1 \dots y@n$ @{text"and"} \dots\ @{text"and"} $z@1 \dots z@m$ @{text"rule:"} $r$@{text")"} -\end{quote} +where $y@1, \dots, y@n$ are variables in the conclusion of the first subgoal. A further useful induction rule is @{thm[source]length_induct}, induction on the length of a list\indexbold{*length_induct}