quoted "if";

--- a/doc-src/TutorialI/Advanced/simp.thy	Tue Jun 06 15:02:55 2006 +0200
+++ b/doc-src/TutorialI/Advanced/simp.thy	Tue Jun 06 16:07:10 2006 +0200
@@ -42,7 +42,7 @@
 Only the first argument is simplified; the others remain unchanged.
 This makes simplification much faster and is faithful to the evaluation
 strategy in programming languages, which is why this is the default
-congruence rule for @{text if}. Analogous rules control the evaluation of
+congruence rule for @{text "if"}. Analogous rules control the evaluation of
 @{text case} expressions.
 
 You can declare your own congruence rules with the attribute \attrdx{cong},
@@ -170,7 +170,7 @@
 P \land Q &\mapsto& P,\ Q \nonumber\\
 \forall x.~P~x &\mapsto& P~\Var{x}\nonumber\\
 \forall x \in A.\ P~x &\mapsto& \Var{x} \in A \Longrightarrow P~\Var{x} \nonumber\\
-@{text if}\ P\ @{text then}\ Q\ @{text else}\ R &\mapsto&
+@{text "if"}\ P\ @{text then}\ Q\ @{text else}\ R &\mapsto&
  P \Longrightarrow Q,\ \neg P \Longrightarrow R \nonumber
 \end{eqnarray}
 Once this conversion process is finished, all remaining non-equations

--- a/doc-src/TutorialI/Misc/simp.thy	Tue Jun 06 15:02:55 2006 +0200
+++ b/doc-src/TutorialI/Misc/simp.thy	Tue Jun 06 16:07:10 2006 +0200
@@ -330,7 +330,7 @@
 text{*
 Polished proofs typically perform splitting within @{text simp} rather than 
 invoking the @{text split} method.  However, if a goal contains
-several @{text if} and @{text case} expressions, 
+several @{text "if"} and @{text case} expressions, 
 the @{text split} method can be
 helpful in selectively exploring the effects of splitting.
 

--- a/doc-src/TutorialI/Recdef/simplification.thy	Tue Jun 06 15:02:55 2006 +0200
+++ b/doc-src/TutorialI/Recdef/simplification.thy	Tue Jun 06 16:07:10 2006 +0200
@@ -7,7 +7,7 @@
 recursion equations become simplification rules, just as with
 \isacommand{primrec}. In most cases this works fine, but there is a subtle
 problem that must be mentioned: simplification may not
-terminate because of automatic splitting of @{text if}.
+terminate because of automatic splitting of @{text "if"}.
 \index{*if expressions!splitting of}
 Let us look at an example:
 *}
@@ -26,7 +26,7 @@
 the recursive call inside the @{text else} branch, which is why programming
 languages and our simplifier don't do that. Unfortunately the simplifier does
 something else that leads to the same problem: it splits 
-each @{text if}-expression unless its
+each @{text "if"}-expression unless its
 condition simplifies to @{term True} or @{term False}.  For
 example, simplification reduces
 @{term[display]"gcd(m,n) = k"}
@@ -35,7 +35,7 @@
 where the condition cannot be reduced further, and splitting leads to
 @{term[display]"(n=0 --> m=k) & (n ~= 0 --> gcd(n, m mod n)=k)"}
 Since the recursive call @{term"gcd(n, m mod n)"} is no longer protected by
-an @{text if}, it is unfolded again, which leads to an infinite chain of
+an @{text "if"}, it is unfolded again, which leads to an infinite chain of
 simplification steps. Fortunately, this problem can be avoided in many
 different ways.
 
@@ -43,10 +43,10 @@
 @{thm[source]split_if},
 as shown in \S\ref{sec:AutoCaseSplits}.  However, we do not recommend this
 approach: you will often have to invoke the rule explicitly when
-@{text if} is involved.
+@{text "if"} is involved.
 
 If possible, the definition should be given by pattern matching on the left
-rather than @{text if} on the right. In the case of @{term gcd} the
+rather than @{text "if"} on the right. In the case of @{term gcd} the
 following alternative definition suggests itself:
 *}
 
@@ -61,7 +61,7 @@
 @{prop"n ~= (0::nat)"}.  Unfortunately, in general the case distinction
 may not be expressible by pattern matching.
 
-A simple alternative is to replace @{text if} by @{text case}, 
+A simple alternative is to replace @{text "if"} by @{text case}, 
 which is also available for @{typ bool} and is not split automatically:
 *}
 
@@ -88,7 +88,7 @@
 
 text{*\noindent
 Simplification terminates for these proofs because the condition of the @{text
-if} simplifies to @{term True} or @{term False}.
+"if"} simplifies to @{term True} or @{term False}.
 Now we can disable the original simplification rule:
 *}
 

--- a/doc-src/ZF/If.thy	Tue Jun 06 15:02:55 2006 +0200
+++ b/doc-src/ZF/If.thy	Tue Jun 06 16:07:10 2006 +0200
@@ -9,8 +9,8 @@
 theory If imports FOL begin
 
 constdefs
-  if :: "[o,o,o]=>o"
-   "if(P,Q,R) == P&Q | ~P&R"
+  "if" :: "[o,o,o]=>o"
+  "if(P,Q,R) == P&Q | ~P&R"
 
 lemma ifI:
     "[| P ==> Q; ~P ==> R |] ==> if(P,Q,R)"