On 8/21/06, Ralf Hemmecke <[EMAIL PROTECTED]> wrote:
>> Looking at this thing I would say that if you take >> >> R = Q[s,c] -- polynomial ring in two variables over rationals >> I = (s^2+c^2-1)R -- ideal in R >> A = R/I -- factor structure >> S = A[[x]] -- formal power series >> >> then S would be a perfect candidate for the result type of the above >> expression. And there is no "Expression Integer". >> While constructing the result of "series", Axiom should try hard to get >> a reasonable (in some sense minimal) type for the result.
The above is a very nice example of a domain for a restricted use, where only the algebraic relation s^2+c^2=1 is important in the coefficients of the power series we wish to work with. I have a very different purpose in mind, and I wonder if anyone can come up with the right type for it. Say I have a few symbols [x,y,z,...] and a binary operagor g. I'm only interested in polynomials or rational functions with, say, integer coefficients in the formal expressions g(x,x), g(x,y), g(y,z), etc. Is there a type that restricts to just this sort of expressions? Expression Integer can handle them, but it will also allow other symbols like a,b,c,... and different operators f(a), h(x,c), etc. None of the Polynomial or similar domains in Axiom can handle this situation because non-symbols like g(x,y). What's the solution? Igor _______________________________________________ Axiom-math mailing list Axiom-math@nongnu.org http://lists.nongnu.org/mailman/listinfo/axiom-math
