Add documentation mention that 7 != NULL also returns NULL.

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index be92e6acb32e5a484ab4112fb270a05906036d62..ddfb29a433813684c60c545dfb124d50020df72a 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -364,8 +364,8 @@
     
     Ordinary comparison operators yield null (signifying unknown),
     not true or false, when either input is null.  For example,
-    7 = NULL yields null.  When this behavior is not suitable,
-    use the
+    7 = NULL yields null, as does 7 <> NULL.  When
+    this behavior is not suitable, use the
     IS  NOT  DISTINCT FROM constructs:
 
 expression IS DISTINCT FROM expression