I've got an idea for a toolkit that uses boost::lambda to let you write 'equations' on the fly in c++. For instance, consider the following pseudo-code: ================== Equation e = x + y; print e(x -> 5, y -> 10) // Prints 15 e = x - y print e(x -> 5, y -> 10) // Prints -5 Equation d = eq(e) + z print d(x -> 1, y -> 2, z -> 3) // Prints 2 ================== The idea is that you can encapsulate an algebraic function in a standalone 'Equation' instance, and dynamically reassign that equation. It's built off of boost::lambda (of course), but it lets you name the variables rather than just refer to them with the standard placeholders (_1, _2, etc.). Is it worthwhile for me to post the toolkit code on this group? Thanks, --Steve Stephen Gross Case Western School of Medicine Cleveland, OH "By Grabthar's hammer, by the sons of Worvan, you shall be avenged." - Dr. Lazarus