In fact, I think that this feature is explicitely allowed and that, as long as you stay within the sage library, code should not break for having a ring with repeated variables.
However, I agree that it is weird. Funny example: sage: K=QQ['x,y,y,x'] sage: sum(K.gens()) x + y + y + x sage: _(x=1,y=2) x + y + 3 -- 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.
