remove rectractall/1 (built-in since 8188e3d0cfde3f2277232a5e9ff2931873211af6).
This resolves
@@ -1902,12 +1902,6 @@ label([], _, Selection, Order, Choice, Optim0, Consistency, Vars) :-
retractall(extremum(_)))
).
-retractall(What) :-
- ( \+ \+ retract(What) ->
- retractall(What)
- ; true
- ).
-
% Introduce new variables for each min/max expression to avoid
% reparsing expressions during optimisation.
