> .map_coefficients doesn't produce an element of the same parent in this case (here it is returning a malformed Sage object). In this example it is sending a symmetric function with coefficients in the ring QQ to a symmetric function with coefficients that are factor objects. It however is not aware that the object that it is producing is not valid. What is going "wrong" is that it is throwing away empty factors (or in this case factor(1) or even factor(-1)). Technically this is also not wrong either because you want empty factors to be 'False' for other applications.
Sorry, I should have made myself clearer: I do not understand the design decision behind the way map_coefficients works. Shouldn't it rather check whether the function actually produces something in the coefficient ring? Martin -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel. For more options, visit https://groups.google.com/d/optout.
