MathPHP\SetTheory\SetAxiomsTest::testAIsSubsetOfAUnionB PHP Method

    public function testAIsSubsetOfAUnionB(Set $A, Set $B)
    {
        $A∪B = $A->union($B);
        $this->assertTrue($A->isSubset($A∪B));
        $this->assertTrue($B->isSubset($A∪B));
    }