The output image of the first hologram has been created to be a 
    point exactly in the middle of the output square as projected from the
    left side.  By flipping the wave front over, and placing it on the
    right hand side, its image arrives at the same spot as projected from
    the right hand side.

      Ok, let's flip the wavefront from which the first hologram was
    made.  The syntax is: FIMAGE IMAGE1 IMAGE3. 
    The input filename is placed first on the command line, then the  
    output filename.