I'd like to make some animations for a presentation showing math function-like substitutions. For example, given
f(x) = x + x
the animation would show starting with both, then
2 being substituted for
x + x, and the result of that replacing
f(2), with the various items sliding around the screen so you can see the substitution happening visually.
What I really need is to show substitution for lambda calculus expressions, like
(\x.x) (\x.x), which is very similar, so if there's software tailored for that, even better.