We talked about this once, afair it is the same in Magma. Really, there is no reason for forbidding it. And deep inside your own code you might want to add a variable to a polynomial ring given to you by the user, and it would be inconvenient to have to pick a letter that is not yet present in the user input.
On Monday, September 29, 2014 3:38:34 PM UTC+1, Joao Alberto de Faria wrote: > > While reviewing some code, I realized that the following is currently > allowed: > P.<x,x,x,x,x,x> = PolynomialRing(QQ,6) > P > > Multivariate Polynomial Ring in x, x, x, x, x, x over Rational Field > > I believe that an object should not be allowed to have repeat instances of > the same variable names. I don't get any actual wrong answers, but I feel as > if it > should be addressed. > > After looking around, I have found two separate instances in the code base > for _assign_names, in category_object.pyx and parent_gens.pyx, both in > sage/structure. I think that the code should check for duplicates at this > point. However this seems too high up in the sage hierarchy for me to want to > mess around with it in good conscious. > > Is there any reason the code currently operates as is? Or do people agree > that this needs to be fixed? > > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
