public function inotn($width)
    {
        assert(is_integer($width) && $width >= 0);
        $neg = false;
        if( $this->isNeg() )
        {
            $this->negi();
            $neg = true;
        }

        for($i = 0; $i < $width; $i++)
            $this->bi = $this->bi->setbit($i, !$this->bi->testbit($i));

        return $neg ? $this->negi() : $this;
    }