On Jul 29, 9:51 am, Simon King <[email protected]> wrote: > 4) > sage: SR(p) > BOOM
shouldn't there at least be some consistency in the *characteristic* of the symbolic ring? I can see how someone might want to make a "symbolic ring of characteristic p", but mixing different characteristics can't possibly lead to good things. sage: T=exp(SR(GF(5)['x']([1,2,3])))+exp(SR(GF(7)['x']([3,6]))) sage: T.operands()[0].operands()[0].operands()[1].pyobject().parent() Finite Field of size 7 sage: T.operands()[1].operands()[0].operands()[1].pyobject().parent() Finite Field of size 5 sage: T(x=1) 10.1073379273897 sage: D=T.diff(x) sage: D(x=1) TypeError: unsupported operand parent(s) for '*': 'Finite Field of size 5' and 'Real Field with 53 bits of precision' so, regarding 4) I'd say the bug is that not more things say BOOM. Incidentally, number fields also do no coerce into SR: sage: K.<r>=NumberField(x^2+3) sage: SR(K['y']([1,2,r+1])) TypeError: unsupported operand parent(s) for '*': [...] so that non-primitive finite fields do not coerce into SR is at least consistent with that. -- To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
