add >=< word to math.order

core/math/order/order-docs.factor

@@ -15,6 +15,12 @@ HELP: <=>
     }
 } ;
 
+HELP: >=<
+{ $values { "obj1" object } { "obj2" object } { ">=<" "an ordering specifier" } }
+{ $description "Compares two objects using the " { $link <=> } " comparator and inverts the output." } ;
+
+{ <=> >=< } related-words
+
 HELP: +lt+
 { $description "Output by " { $link <=> } " when the first object is strictly less than the second object." } ;
 
@@ -85,6 +91,7 @@ ARTICLE: "order-specifiers" "Ordering specifiers"
 ARTICLE: "math.order" "Linear order protocol"
 "Some classes have an intrinsic order amongst instances:"
 { $subsection <=> }
+{ $subsection >=< }
 { $subsection compare }
 { $subsection invert-comparison }
 "The above words output order specifiers."

core/math/order/order.factor

@@ -13,6 +13,8 @@ SYMBOL: +gt+
 
 GENERIC: <=> ( obj1 obj2 -- <=> )
 
+: >=< ( obj1 obj2 -- >=< ) <=> invert-comparison ; inline
+
 M: real <=> 2dup < [ 2drop +lt+ ] [ number= +eq+ +gt+ ? ] if ;
 
 GENERIC: before? ( obj1 obj2 -- ? )