Dear Dima, > On 21 Sep 2017, at 11:51, dmitrii.pasech...@cs.ox.ac.uk wrote: > > Dear all, > > I'd like to write a function that takes a multivariate polynomial p > and produces another polynomial in the same polynomial ring R, > by doing a variable subsitution. > > Is there a way to p about its ring, > or at least about the family of the indeterminants of the ring?
No, this is not possible, you haven't missed anything in the manual: All polynomials implicitly "live in" the polynomial ring with "all" (infinitely many) indeterminates. Of course you can "cheat" and define the action on pairs [indet, polys] where the first entry is a list of indeterminates you want to act on. Or do you what you described in your mail (which just passes "indet" implicitly via a higher variable in the scope in which you action is defined). Regards, Max _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
