Hi Joris! On Jul 27, 11:53 am, jvkersch <joris.vankerscha...@gmail.com> wrote: > File "element.pyx", line 472, ... > ... > AssertionError
The line numbers (e.g., line 472 in element.pyx) might give you a hint what happens. My line numbers seem a bit different, but at line 473 of element.pyx, in method _test_category, there is tester.assert_(isinstance(self, self.parent().category().element_class)) and indeed, you get an AssertionError. It would of course be nice to get an actual error message with the AssertionError. However, the place of the error seems to indicate that you have an element of your parent, but your element is not of the expected class. Cheers, Simon -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org