lib/BN.php
public function imul(BN $num) {
        $this->bi = $this->bi->mul($num->bi);
        return $this;
    }
public function imul(BN $num) {
        $this->bi = $this->bi->mul($num->bi);
        return $this;
    }
public function imul ( BN $ num ) { $ this -> bi = $ this -> bi -> mul ( $ num -> bi ) ; return $ this ; }
In-place Multiplication
In - place Multiplication