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poss(?SetVariable, -Poss)

Obtaining the still possible elements of a set (lub\glb)
SetVariable
A set variable.
Poss
A set.

Description

Poss is unified with the set of still possible elements of SetVariable (i.e. its lub\glb).

If SetVariable is a set of sets and a union function attribute has been set, then each element of Poss comes annotated with its respective length.

Fail Conditions

Fails if Poss can not be unified with the current poss (lub\glb) of SetVariable.

Resatisfiable

No.

Examples

?- S `::[c]+[a,b], poss(S,P).
P = [a,b]

?- S `::[[c]]+[[a,b]], poss(S,P).
P = [[a,b]]

?- set(S, [],[[a,b],[b,c],[a,c],[b]],[union:[a,b,c]]), poss(S,P).
P = [[a, b] : 2, [a, c] : 2, [b] : 1, [b, c] : 2]

See Also

glb / 2, glb_poss / 3, domain / 2, domain / 3, lub / 2, lub / 4