symbolic differentiation, pt 2
Now that we've got a basic symbolic differentiator (and the numeric one), we could simplify the expressions. SICP gives some basic simplifications.
(+ 0 x) => x
or additive identity(* 1 x) => x
or multiplicative identity(+ 1 2) => 3
or constant simplification(* 3 2) => 6
or constant simplification
Here's the relevant link into SICP, for reference.
The challenge this week is to integrate these easy simplifications into the differentiator. If you didn't do last week's challenge, grab someone else's code and work from that.