>Really? Just use boolian limiters. For example, if you have the >function: >F(x) = 2x if X<0 >F(x) = X^2 of X >= 0 > >then all you have to do is. >y1 = (2x)/(X<0) >y2 = (x^2)/(X>=0) Are you sure you want to DIVIDE? Shouldn't it be multiplied? y1 = (2x)(x<0) y2 = (x^2)(x>=0) Tom Lake