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vs_random_worst(+VS, -X)

Retrieve a worst violated variable from a varset
VS
A varset
X
Tentative variable (output)

Description

Retrieve a variable from a varset whose violation count is maximal in the varset. In case of ties, a random candidate is returned.

Modes and Determinism

Fail Conditions

Fails if there is no violated variable in the set

Examples

    ?- Vars=[A,B,C], tent_set(Vars, [1,2,3]), vs_create(Vars, VS),
       var_inc_violations(A, 2),
       var_inc_violations(B, 1),
       var_inc_violations(C, 2),
       vs_random_worst(VS, Worst).
    Vars = [A{1 -> 2}, B{2 -> 1}, Worst{3 -> 2}]
    VS = ...
    Worst = Worst{3 -> 2}       % A or C, the result is random!
    Yes (0.00s cpu)

See Also

vs_all_worst / 2, vs_worst / 2, vs_random_worst_index / 2