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# constraints_number(?Var, ?N)

The number of constraints and suspended goals associated with the variable Var is N.

?Var
  Prolog term
?N
  Variable or integer

## Description

N is the number of constraints and suspended goals currently attached to the variable Var. Note that this number may not correspond to the exact number of different constraints attached to Var, as goals in different suspending lists are counted separately. This predicate is often used when looking for the most or least constrained variable from a set of domain variables. If Var is instantiated, N is bound to a very large integer, if Var is a free variable, N is zero.

### Fail Conditions

None.

### Resatisfiable

No.

## See Also

:: / 2, #:: / 2, deleteff / 3, deleteffc / 3