lib/BN.php
public function iuand(BN $num) {
        $this->bi = $this->bi->binaryAnd($num->bi);
        return $this;
    }
public function iuand(BN $num) {
        $this->bi = $this->bi->binaryAnd($num->bi);
        return $this;
    }
public function iuand ( BN $ num ) { $ this -> bi = $ this -> bi -> binaryAnd ( $ num -> bi ) ; return $ this ; }
And `num` with `this` in-place
And num with this in - place