Putting "y1=y2" in for y3 works well for this, except when comparing functions with different data types. For example, y=x and y=Sqrt(x) don't work....so I think "real(y1)=real(y2)" works better. If anyone has other ideas for finding equivalence of functions, please share it!! Thanks. -Tom Lutz caffeine43@netzero.net on 06/09/2001