Hallo all! I have found the following bug which mostly occurs when substituting power series over inexact rings. E.g.
R.<x> = CC[[]] x.subs(x = x**2) gives x*. *Same for the base field Qp(7). The reason is that the generic method subs iterates the generators of R (in this case x) and checks whether any keyword matches the string representation of that generator. But x._repr_() does not give 'x', but 0.0... + 1.0... x. There are two obvious ways to fix this: Change _repr_ or change subs. By changing _repr_, we would accept that some elements are wrongly printed as exact elements, but this approach would correspond to the fact that CC(0) == CC(0) is true. By changing subs, we would introduce a specialized method for power series rings, while so far any ParentWithGens comes with the same implementation. I would rather change _repr_. What do you think? Best, Martin -- -- 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
