> Why not use a Computer Algebra System instead for generating derivatives of given functions? You will generate expressions, and evaluating those expressions

> Why not use a Computer Algebra System instead for generating derivatives of given functions? You will generate expressions, and evaluating those expressions leads to the execution of exactly the same elementary operations as with forward mode AD. But with the overhead of needing the Computer Algebra System, and storing the expressions. (Ok, in some cases the CAS is maybe able to simplify the expressions a bit.)