MathPHP\SetTheory\Set::isProperSuperset PHP Метод

    public function isProperSuperset(Set $B) : bool
    {
        $B_array = $B->asArray();
        $A∩B = array_intersect_key($this->A, $B_array);
        $A∖B = array_diff_key($B_array, $this->A);
        return count($A∩B) === $B->length() && empty($A∖B) && $this != $B;
    }

 /**
  * @dataProvider dataProviderForIsProperSet
  */
 public function testIsProperSuperset(array $A, array $B)
 {
     $setA = new Set($B);
     $setB = new Set($A);
     $this->assertFalse($setA->isProperSuperset($setB));
 }