Maxima-like output of mathematical equations.

[nineties]

like this.

(%i1) diff(f(x)^g(x), x);
                                                      d
                                                g(x) (-- (f(x)))
                  g(x)             d                  dx
(%o1)         f(x)     (log(f(x)) (-- (g(x))) + ----------------)
                                   dx                 f(x)