PS: On 12 Dez., 19:07, Simon King <[email protected]> wrote: [...] > So, I don't suggest that conversion should always attempt to be name > preserving.
But 'fetch' can't be the final answer either. Here, we have to keep in mind that the coercion system wants to use pushout. Imagine: sage: R1.<a,b,x> = QQ[] sage: R2.<b,x,y> = QQ[] sage: from sage.categories.pushout import pushout sage: pushout(R1,R2) Multivariate Polynomial Ring in a, b, x, y over Rational Field Now, for multiplying a and y, both would be mapped to the pushout. If this was done by fetch, the result would be sage: a*y a*x So, neither fetch nor imap yields a thoroughly consistent and satisfying coercion. However, it would be good to have wrappers for imap and fetch handy. Cheers, Simon -- 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
