The iterated subs turns out to be correct sage: F.subs(X=4).subs(Y=2) 0 sage: F.subs(Y=2).subs(X=4) 0
But not the one shot version (which is supposedly equivalent to the evaluation) sage: F.subs(X=4, Y=2) 6 There is definitely something wrong!! Vincent On Tue, 27 Sept 2022 at 10:46, John Cremona <john.crem...@gmail.com> wrote: > > Am I doing something stupid here, or is this a bug? > > sage: R = Integers(8) > sage: RXY.<X,Y> = R[] > sage: F = X^3-X^2*Y+X*Y^2+Y^3 > sage: F([4,2]) > 6 > sage: 4^3-4^2*2+4*2^2+2^3 > 56 > sage: (4^3-4^2*2+4*2^2+2^3) % 8 > 0 > > > Why does F not evaluate to 0 mod 8 at X=4, Y=2? Rather obviously, each > of the terms in F(4,2) is 0 mod 8. > > John > > -- > You received this message because you are subscribed to the Google Groups > "sage-support" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-support+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sage-support/CAD0p0K5hXexw5J20gstKUOXxzWdP2a2OTRbKmUtAyG41ySSR-A%40mail.gmail.com. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/CAGEwAAm12%3DBhuPHvb2WHzn0HfUJb%3DKcS_E5h8YiZ14Z5MEL9Mw%40mail.gmail.com.
