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# ?SetVar1 `/= ?SetVar2

Set inequality constraint
*SetVar1*
- A set variable.
*SetVar2*
- A set variable.

## Description

Constrain sets SetVar1 and SetVar2 to be different.
This constraint is suspended until one of the two sets is bound
to another set (variable or ground).

### Fail Conditions

Fails if SetVar1 and SetVar2 must be the same set.
### Resatisfiable

No.
## Examples

?- [] `/= [8], [7] `/= [8], [7,8] `/= [8], [7] `/= [7,8].
yes
?- [] `/= [] ; [a] `/= [a] ; [a,b] `/= [b,a].
no
?- sets([X,Y], [],[8,9], [cardinality:1]), X `/= Y, set_labeling([X,Y]).
X = [8], Y = [9] ;
X = [9], Y = [8] ;
no
?- sets([X,Y], [],[8,9], []), X `/= Y, X=Y.
no
?- X `:: [8]+[8,9], [8,9] `/= X, card_labeling([X]).
X = [8] ;
no

## See Also

`$ / 2, complement / 2, complement / 3, `= / 2