diff -r 2995639c6a09 -r 90695f46440b doc-src/TutorialI/Ifexpr/Ifexpr.thy --- a/doc-src/TutorialI/Ifexpr/Ifexpr.thy Fri Jan 12 16:28:14 2001 +0100 +++ b/doc-src/TutorialI/Ifexpr/Ifexpr.thy Fri Jan 12 16:32:01 2001 +0100 @@ -2,7 +2,7 @@ theory Ifexpr = Main:; (*>*) -subsection{*Case study: boolean expressions*} +subsection{*Case Study: Boolean Expressions*} text{*\label{sec:boolex} The aim of this case study is twofold: it shows how to model boolean @@ -10,7 +10,7 @@ the constructs introduced above. *} -subsubsection{*How can we model boolean expressions?*} +subsubsection{*How Can We Model Boolean Expressions?*} text{* We want to represent boolean expressions built up from variables and @@ -28,7 +28,7 @@ For example, the formula $P@0 \land \neg P@1$ is represented by the term @{term"And (Var 0) (Neg(Var 1))"}. -\subsubsection{What is the value of a boolean expression?} +\subsubsection{What is the Value of a Boolean Expression?} The value of a boolean expression depends on the value of its variables. Hence the function @{text"value"} takes an additional parameter, an @@ -44,7 +44,7 @@ "value (And b c) env = (value b env \ value c env)"; text{*\noindent -\subsubsection{If-expressions} +\subsubsection{If-Expressions} An alternative and often more efficient (because in a certain sense canonical) representation are so-called \emph{If-expressions} built up @@ -66,8 +66,9 @@ else valif e env)"; text{* -\subsubsection{Transformation into and of If-expressions} +\subsubsection{Transformation Into and of If-Expressions} +\REMARK{is this the title you wanted?} The type @{typ"boolex"} is close to the customary representation of logical formulae, whereas @{typ"ifex"} is designed for efficiency. It is easy to translate from @{typ"boolex"} into @{typ"ifex"}: