2021-11-16 11:32:19 +0200 marked best answer Create group with custom set and operator Hi, I know that we can use Sage to create an instance of a predefined group like so: H = DihedralGroup(6)  But instead of using a predefined group, can I also create a group instance having a predefined set (for example a set of natural numbers) and a custom binary operator (such as multiplication modulo N) ? What I'm looking for is something like this: G = new Group({1, 2, 3, 4}, (a, b) -> a * b mod 10)  And then generate the group table for G. If someone could provide me with an code example it'd be great, I wasn't able to derive it from the docs I read. 2021-11-16 11:32:19 +0200 received badge ● Scholar (source) 2021-11-06 16:46:30 +0200 commented answer Create group with custom set and operator Thanks for your reply, but I was actually indeed talking about groups. The example was just for illustrative purposes, I 2021-10-27 15:08:13 +0200 received badge ● Student (source) 2021-10-27 11:19:38 +0200 asked a question Create group with custom set and operator Create group with custom set and operator Hi, I know that we can use Sage to create an instance of a predefined group li