Hi, I was thinking I might make it into a series of kata where you add more functions one at a time if this one went down well. I saw that in a Morse code kata and liked the idea. There are other interesting properties of groups that could be interesting to implement like finding subgroups or proving two groups are isomorphic.

No idea how that happened

Good catch! I forgot to change my original code rather than just the template, updated Thanks!

I've come up with three more tests that I think catch, associtivity, lack of identity and lack of an inverse while retaining the other three conditions. Thanks for the advice.

Thank you! I don't know how I missed that, I didn't realise that when you press validate soloutions it doesn't check the examples.
I've fixed it.

Thank you for the link, I haven't done much programmaing before so I'm new to style guides. I think I've made it better, following the style for functions and variables.