spec/im/Primitive/Int/IntSpec.php
function it_should_plus_values()
    {
        $plus = 10;

        $this->plus($plus)->value()->shouldBe($this->init + $plus);
    }
function it_should_plus_values()
    {
        $plus = 10;

        $this->plus($plus)->value()->shouldBe($this->init + $plus);
    }
Math