1.1 --- a/doc-src/ZF/FOL.tex Wed Aug 20 11:12:48 2003 +0200
1.2 +++ b/doc-src/ZF/FOL.tex Wed Aug 20 13:05:22 2003 +0200
1.3 @@ -259,8 +259,9 @@
1.4 IntPr.fast_tac : int -> tactic
1.5 IntPr.best_tac : int -> tactic
1.6 \end{ttbox}
1.7 -Most of these belong to the structure \ML{} \texttt{IntPr} and resemble the
1.8 -tactics of Isabelle's classical reasoner. Note that you can use the
1.9 +Most of these belong to the structure \ML{} structure \texttt{IntPr} and resemble the
1.10 +tactics of Isabelle's classical reasoner. There are no corresponding
1.11 +Isar methods, but you can use the
1.12 \isa{tactic} method to call \ML{} tactics in an Isar script:
1.13 \begin{isabelle}
1.14 \isacommand{apply}\ (tactic\ {* IntPr.fast\_tac 1*})
1.15 @@ -350,12 +351,14 @@
1.16
1.17
1.18 \section{An intuitionistic example}
1.19 -Here is a session similar to one in {\em Logic and Computation}
1.20 -\cite[pages~222--3]{paulson87}. Isabelle treats quantifiers differently
1.21 -from {\sc lcf}-based theorem provers such as {\sc hol}.
1.22 +Here is a session similar to one in the book {\em Logic and Computation}
1.23 +\cite[pages~222--3]{paulson87}. It illustrates the treatment of
1.24 +quantifier reasoning, which is different in Isabelle than it is in
1.25 +{\sc lcf}-based theorem provers such as {\sc hol}.
1.26
1.27 -The theory header must specify that we are working in intuitionistic
1.28 -logic:
1.29 +The theory header specifies that we are working in intuitionistic
1.30 +logic by designating \isa{IFOL} rather than \isa{FOL} as the parent
1.31 +theory:
1.32 \begin{isabelle}
1.33 \isacommand{theory}\ IFOL\_examples\ =\ IFOL:
1.34 \end{isabelle}
1.35 @@ -524,7 +527,7 @@
1.36 $\ex{y}\all{x}P(y)\imp P(x)$. Informally, the theorem can be proved as
1.37 follows. Choose~$y$ such that~$\neg P(y)$, if such exists; otherwise
1.38 $\all{x}P(x)$ is true. Either way the theorem holds. First, we must
1.39 -work in a theory based on classical logic:
1.40 +work in a theory based on classical logic, the theory \isa{FOL}:
1.41 \begin{isabelle}
1.42 \isacommand{theory}\ FOL\_examples\ =\ FOL:
1.43 \end{isabelle}