The combine method



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> I used "funmake(f, inverse_outative(q,f))" in "inverse_additive(e,f)". But should I use "funmake(f, q)" ?

Your code does

  (%i16) inverse_additive(f(f(5))+f(f(x)),f);
  (%o16) f(f(x)+f(5))

  (%i17) inverse_additive(%,f);
  (%o17) f(f(x+5))

One way to fix this is to replace inverse_additive(e,f) with funmake(f, inverse_outative(q,f)).  An alternative would be to
write a utility that repeatedly applies a function until the expression stops changing (fixed point iteration). Maybe there
is such a function in Maxima?

--Barton