--- a/src/HOL/Orderings.thy Wed Feb 10 14:12:02 2010 +0100
+++ b/src/HOL/Orderings.thy Wed Feb 10 14:12:04 2010 +0100
@@ -11,6 +11,41 @@
"~~/src/Provers/quasi.ML" (* FIXME unused? *)
begin
+subsection {* Syntactic orders *}
+
+class ord =
+ fixes less_eq :: "'a \<Rightarrow> 'a \<Rightarrow> bool"
+ and less :: "'a \<Rightarrow> 'a \<Rightarrow> bool"
+begin
+
+notation
+ less_eq ("op <=") and
+ less_eq ("(_/ <= _)" [51, 51] 50) and
+ less ("op <") and
+ less ("(_/ < _)" [51, 51] 50)
+
+notation (xsymbols)
+ less_eq ("op \<le>") and
+ less_eq ("(_/ \<le> _)" [51, 51] 50)
+
+notation (HTML output)
+ less_eq ("op \<le>") and
+ less_eq ("(_/ \<le> _)" [51, 51] 50)
+
+abbreviation (input)
+ greater_eq (infix ">=" 50) where
+ "x >= y \<equiv> y <= x"
+
+notation (input)
+ greater_eq (infix "\<ge>" 50)
+
+abbreviation (input)
+ greater (infix ">" 50) where
+ "x > y \<equiv> y < x"
+
+end
+
+
subsection {* Quasi orders *}
class preorder = ord +