1 files changed, 1 insertions, 1 deletions
diff --git a/stdlib.pl b/stdlib.pl
index 01b3e5f..cceada6 100644
--- a/stdlib.pl
+++ b/stdlib.pl
@@ -61,7 +61,7 @@ A @>= B :-
 length([], 0).
 length([_|Tail], Length) :-
 	length(Tail, Length0),
-	Length is Length + 1.
+	Length is Length0 + 1.
 
 member(X, [X|_]).
 member(X, [_|Tail]) :-