Bill Allombert on Sat, 3 Nov 2001 00:31:02 +0100 |
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Re: subst() broken |
> I cannot "remember" it because priorities are not documented. I find > some unintelligible hints (in the section "Polmods"); some other > *hints* in "Type t_POLMOD (polmod)' (without definition of what is a > priority); and a kinda-definition in "PARI variables" (without > mentioning the relation to the time flow). Yes you can, since we already discuss it in this mailing list :-) > > Probably you mean (1+y)*Mod(1,z), but it is not the same thing: > > it is a polynomial not a POLMOD. > > I have no slightest idea what you mean by this sentence. Can it be > expressed algebraically, or it is just some "implementation detail"? Both. (1+y)*Mod(1,z) is an object living in the ring (Q[Z]/(Z))[Y], so it is a polynomial in Y whose coeffcients are cosets in Z. Mod(1+y,z) is an object living in Q(Z)[Y]/(Z) so it is a coset, but the ideal (Z) being trivial because Z is invertible, this quotient is the null ring. Hopes I have answered your question. Bill.