def collide(ax0, ay0, ax1, ay1, bx0, by0, bx1=None, by1=None):
    """Return True if the two rectangles intersect."""
    if bx1 is None:
        bx1 = bx0
    if by1 is None:
        by1 = by0
    return not (ax1 < bx0 or ay1 < by0 or ax0 > bx1 or ay0 > by1)