public function testUnionDistributive(Set $A, Set $B, Set $C)
{
$A∪⟮B∩C⟯ = $A->union($B->intersect($C));
$⟮A∪B⟯∩⟮A∪C⟯ = $A->union($B)->intersect($A->union($C));
$this->assertEquals($A∪⟮B∩C⟯, $⟮A∪B⟯∩⟮A∪C⟯);
$this->assertEquals($A∪⟮B∩C⟯->asArray(), $⟮A∪B⟯∩⟮A∪C⟯->asArray());
}