2.3 IsRelation

IsRelation( obj )

IsRelation returns true if obj, which may be an object of arbitrary type, is a relation and false otherwise. It will signal an error if obj is an unbound variable.

    gap> IsRelation( 1 );
    false
    gap> IsRelation( Relation(  [ [ 1 ], [ 2 ], [ 3 ] ] ) );
    true 

   
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