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# vs_random_worst_index(+VS, -Var)

Retrieve a worst violated variable index from a varset

VS
  A varset
Var
  An integer (output)

## Description

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

### Modes and Determinism

- vs_random_worst_index(+, -) is semidet

### 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 = 1       % 1 or 3, the result is random!
        Yes (0.00s cpu)

## See Also

vs_all_worst_index / 2, vs_worst_index / 2, vs_random_worst / 2