MathPHP\LinearAlgebra\Vector::perp PHP Method

    public function perp(Vector $B) : Vector
    {
        $A⋅B⊥ = $B->perpDotProduct($this);
        $│B│² = $B->l2norm() ** 2;
        $B⊥ = $B->perpendicular();
        return $B⊥->scalarMultiply($A⋅B⊥ / $│B│²);
    }