I agree, it isn't the greatest example for showing the power of Lisp. Here's a much better one that uses a macro to do symbolic differentiation in <150 lines:

I agree, it isn't the greatest example for showing the power of Lisp. Here's a much better one that uses a macro to do symbolic differentiation in <150 lines: https://github.com/aksiazek/symbolic-differentiation https://github.com/aksiazek/symbolic-differentiation Much harder to do that in C ;-) Peter Norvig's book "Paradigms of Artificial Intelligence" uses symbolic differentiation as an example in one of the early chapters.