okay, so if i wrote X in terms of y,z,w (e.g. x= -2y-3z-4w) and substituted that into X, which then becomes [-2y-3z-4w 2y 3z 4w], then that is basis consisting of the span of all perpendicular vectors to [1 2 3 4]? In other words, if I took the dot product of those, then it would be zero?