def _v3_isub_  ( s , other ) :
    """Increment 4-vector with another 3-vector
    >>> v3  = ...
    >>> v3 -= other
    """
    s.SetX     ( s.X () - other.X () )
    s.SetY     ( s.Y () - other.Y () )
    s.SetZ     ( s.Z () - other.Z () )
    return s