
?Element `-@ ?SetVariable

   Set non-membership constraint

Arguments
   SetVariable         A set variable.
   Element             A ground term or a variable.

Type
   library(cardinal)

Description
Constrain SetVariable to not include Element.
		If Element is a variable then the constraint
		is suspended until it becomes ground.

Fail Conditions
   Fails if Element must be a member of SetVariable.

Resatisfiable
   No.

Examples
   
?- S `:: []..[a,b], a `-@ S, glb_poss(S,G,P).
G = [], P = [b]

?- S `:: [c]+[a,b], c `-@ S.
no

?- S `:: [a]+[b,c], z `-@ S, glb_poss(S,G,P).
G = [a], P = [b,c]

?- S `:: []..[a,b], X `-@ S, glb_poss(S,G,P).
G = [], P = [a,b]

?- S `:: []..[a,b], X `-@ S, X=b, glb_poss(S,G,P).
G = [], P = [a]


See Also
   `@ / 2, in / 2, notin / 2, `:: / 2
