diff -r bfcabed9079e -r 949957531f63 ProgTutorial/FirstSteps.thy --- a/ProgTutorial/FirstSteps.thy Tue Jul 21 12:11:24 2009 +0200 +++ b/ProgTutorial/FirstSteps.thy Tue Jul 21 12:27:12 2009 +0200 @@ -1001,11 +1001,6 @@ the file @{ML_file "Pure/thm.ML"}. \end{readmore} - \begin{exercise} - Check that the function defined in Exercise~\ref{fun:revsum} returns a - result that type-checks. - \end{exercise} - Remember Isabelle follows the Church-style typing for terms, i.e., a term contains enough typing information (constants, free variables and abstractions all have typing information) so that it is always clear what the type of a term is. @@ -1038,6 +1033,11 @@ where no error is detected. + \begin{exercise}\label{fun:revsum typed} + Check that the function defined in Exercise~\ref{fun:revsum} returns a + result that type-checks. + \end{exercise} + Sometimes it is a bit inconvenient to construct a term with complete typing annotations, especially in cases where the typing information is redundant. A short-cut is to use the ``place-holder''