--- a/src/HOL/ex/PER.thy Sat Dec 26 15:44:14 2015 +0100
+++ b/src/HOL/ex/PER.thy Sat Dec 26 15:59:27 2015 +0100
@@ -11,8 +11,8 @@
text \<open>
Higher-order quotients are defined over partial equivalence
relations (PERs) instead of total ones. We provide axiomatic type
- classes @{text "equiv < partial_equiv"} and a type constructor
- @{text "'a quot"} with basic operations. This development is based
+ classes \<open>equiv < partial_equiv\<close> and a type constructor
+ \<open>'a quot\<close> with basic operations. This development is based
on:
Oscar Slotosch: \emph{Higher Order Quotients and their
@@ -25,9 +25,9 @@
subsection \<open>Partial equivalence\<close>
text \<open>
- Type class @{text partial_equiv} models partial equivalence
- relations (PERs) using the polymorphic @{text "\<sim> :: 'a \<Rightarrow> 'a \<Rightarrow>
- bool"} relation, which is required to be symmetric and transitive,
+ Type class \<open>partial_equiv\<close> models partial equivalence
+ relations (PERs) using the polymorphic \<open>\<sim> :: 'a \<Rightarrow> 'a \<Rightarrow>
+ bool\<close> relation, which is required to be symmetric and transitive,
but not necessarily reflexive.
\<close>
@@ -64,7 +64,7 @@
subsection \<open>Equivalence on function spaces\<close>
text \<open>
- The @{text \<sim>} relation is lifted to function spaces. It is
+ The \<open>\<sim>\<close> relation is lifted to function spaces. It is
important to note that this is \emph{not} the direct product, but a
structural one corresponding to the congruence property.
\<close>
@@ -117,8 +117,8 @@
text \<open>
The class of total equivalence relations on top of PERs. It
- coincides with the standard notion of equivalence, i.e.\ @{text "\<sim>
- :: 'a \<Rightarrow> 'a \<Rightarrow> bool"} is required to be reflexive, transitive and
+ coincides with the standard notion of equivalence, i.e.\ \<open>\<sim>
+ :: 'a \<Rightarrow> 'a \<Rightarrow> bool\<close> is required to be reflexive, transitive and
symmetric.
\<close>
@@ -148,7 +148,7 @@
subsection \<open>Quotient types\<close>
text \<open>
- The quotient type @{text "'a quot"} consists of all
+ The quotient type \<open>'a quot\<close> consists of all
\emph{equivalence classes} over elements of the base type @{typ 'a}.
\<close>