src/Malenki/Math/Number/Complex.php
public function substract($z)
    {
        if (is_numeric($z)) {
            $z = new self($z, 0);
        }

        return $this->add($z->negative());
    }
public function substract($z)
    {
        if (is_numeric($z)) {
            $z = new self($z, 0);
        }

        return $this->add($z->negative());
    }
Substracts complex number `z` from the current one.

@param  mixed   $z Complex or real number
@access public
@return Complex