text: Consider a shift in the position of the reference point, say from  to . Let  denote the stream function relative to the shifted reference point :
  Then the stream function is shifted by
  which implies the following:
  * A shift in the position of the reference point effectively adds a constant (for steady flow) or a function solely of time (for nonsteady flow) to the stream function  at every point .
  * The shift in the stream function, , is equal to the total volumetric flux, per unit thickness, through the surface that extends from point  to point . Consequently  if and only if  and  lie on the same streamline.