Why don't just use Blitz++ for various expressions/equations? ;)

I didn't know about blitz++, but I've just now taken a quick look at it. It appears designed for performance above all, which is not the idea behind my equation toolkit. The equation toolkit is designed to let you *easily* write straight-forward equations, combine them, and re-assign them as you want. For instance: ================= Equation e = x + y print e(x -> 1, y -> 2) e = y print e(y -> 9) e = z + 2 * y / a + b print e(a -> 2, b -> 5, y -> 100, z -> 50) ================= The advantage is that you can easily change an equation so you don't actually have to write functions for each equation. If you have a situation where you need to dynamically change around equations a lot during runtime, this system should (ideally) be useful. --Steve