On 2/26/20 4:56 AM, Sagnik Dey wrote: > I was hoping to contribute towards the Sage community in the coming > summer ad thus in preparation, I was going through a few beginner > tickets. I first tried #13649 but in the current code, the > implementation seems to be done already as calling domain on an element > works as intended. Also, codomain is not really defined for the > symmetric group.
This is partly done but the ticket was never updated. If you think of a permutation as a function, its codomain should be the same as its domain, because a permutation (bijectively) rearranges the elements of its domain. For "image" I'm not so sure though. The last proposed patch does something I didn't expect, and defines the image of a permutation to be the set of elements that it does not fix. I would have expected the image to be equal to the codomain, since permutations are surjective. If someone who works with symmetric groups can comment on what "image" should do, adding codomain() and image() should be straightforward. -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/af7e1198-7d15-855d-18bd-591c29d7cc3c%40orlitzky.com.
