diff --git a/prolog/metta_lang/stdlib_mettalog.metta b/prolog/metta_lang/stdlib_mettalog.metta
index bf8e107041..a003962695 100644
--- a/prolog/metta_lang/stdlib_mettalog.metta
+++ b/prolog/metta_lang/stdlib_mettalog.metta
@@ -198,8 +198,8 @@ For example:
 ;; Arity Assignments
 
 (predicate-arity predicate-arity 2)
-(predicate-arity : 2)
-(= (: $F P1) (predicate-arity $F 1))
+;(predicate-arity : 3)
+; (= (: $F P1) (predicate-arity $F 1))
 
 ;; Source Predicate and Function Types