doc-src/TutorialI/Rules/rules.tex
 changeset 10546 b0ad1ed24cf6 parent 10399 e37e123738f7 child 10578 b32513971481
--- a/doc-src/TutorialI/Rules/rules.tex	Thu Nov 30 16:48:38 2000 +0100
+++ b/doc-src/TutorialI/Rules/rules.tex	Thu Nov 30 17:55:17 2000 +0100
@@ -1257,7 +1257,7 @@
%gcd\ (m,\ n)\ dvd\ m\ \isasymand\ gcd\ (m,\ n)\ dvd\ n\isanewline
\ 1.\ {\isasymAnd}m\ n.\ \isasymlbrakk0\ \isacharless\ n;\isanewline
\ \ \ \ \ \ \ \ \ \ \ \ gcd\ (n,\ m\ mod\ n)\ dvd\ n\ \isasymand\ gcd\ (n,\ m\ mod\ n)\ dvd\ (m\ mod\ n){\isasymrbrakk}\isanewline
-\ \ \ \ \ \ \ \ \ \ \isasymLongrightarrow\ gcd\ (n,\ m\ mod\ n)\ dvd\ m
+\ \ \ \ \ \ \ \ \ \ \ \isasymLongrightarrow\ gcd\ (n,\ m\ mod\ n)\ dvd\ m
\end{isabelle}
%
One of the assumptions, the induction hypothesis, is a conjunction.
@@ -1409,19 +1409,17 @@
and {\isa{simp}}.  Also there is \isa{safe}, which like \isa{clarify} performs
obvious steps and even applies those that split goals.

-The {\isa{force}} method applies the classical reasoner and simplifier
+The \isa{force} method applies the classical reasoner and simplifier
to one goal.
-\REMARK{example needed? most
-things done by blast, simp or auto can also be done by force, so why add a new
-one?}
+\REMARK{example needed of \isa{force}?}
Unless it can prove the goal, it fails. Contrast
-that with the auto method, which also combines classical reasoning
+that with the \isa{auto} method, which also combines classical reasoning
with simplification. The latter's purpose is to prove all the
easy subgoals and parts of subgoals. Unfortunately, it can produce
large numbers of new subgoals; also, since it proves some subgoals
and splits others, it obscures the structure of the proof tree.
-The {\isa{force}} method does not have these drawbacks. Another
-difference: {\isa{force}} tries harder than {\isa{auto}} to prove
+The \isa{force} method does not have these drawbacks. Another
+difference: \isa{force} tries harder than {\isa{auto}} to prove
its goal, so it can take much longer to terminate.

Older components of the classical reasoner have largely been
@@ -1434,7 +1432,7 @@
as type classes and function unknowns. For example, the introduction rule
for Hilbert's epsilon-operator has the following form:
\begin{isabelle}
-?P\ ?x\ \isasymLongrightarrow\ ?P\ (Eps\ ?P)
+?P\ ?x\ \isasymLongrightarrow\ ?P\ (SOME\ x.\ ?P x)
\rulename{someI}
\end{isabelle}

@@ -1855,7 +1853,7 @@
\end{isabelle}

Assuming that \isa{z} is not 35, the first subgoal follows by linear arithmetic:
-the method {\isa{arith}}. For the second subgoal we apply the method {\isa{force}},
+the method {\isa{arith}}. For the second subgoal we apply the method \isa{force},
which proceeds by assuming that \isa{z}=35 and arriving at a contradiction.