The transform is implemented via calling of SymPy but apparently something went wrong in the conversion to SymPy. I cannot say more as I'm not at my box but you can try to use SymPy directly as a workaround.
Regards, -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.