I have asked this question on math stack exchange
https://math.stackexchange.com/questions/4853922/michell-fpl-2-3-5-observable-types,
but there has been no answer.
The math stack guidelines are usually to wait 1 week before crossposting, with links to both on the other side. Would that be alright here or is there another ettiquete? I can also delete the question on math stack, since it seems like no one will answer.
Thank you for asking! I appreciate that.
The official rules are here: Is cross-posting a question on multiple Stack Exchange sites permitted if the question is on-topic for each site?.
I suggest deleting the copy on Math.SE before posting here. Personally, I have had bad experiences with cross-posts, where someone posts an answer on one copy and people on the other copy don't notice it is already answered, someone leaves feedback on one copy and readers of the other copy don't notice, edits are made to one copy but not the other, etc. Since we're trying to be an archive of knowledge, I think it works better if answers and feedback are all concentrated in one place.
Separately:
I'm not sure whether your question is going to be well received here in its current form. It seems to be a "proof verification" / "is my answer correct?" type of question. Those generally don't contribute much to our mission of building up an archive of knowledge. Asking someone to check an entire proof is usually a bit much to ask, and then the answer is only "Correct" or "Incorrect", which typically isn't very helpful to others. Our guidance on those questions is that you must identify a single aspect of your particular solution that you want to ask about (e.g., some specific doubt about one step in your solution), but don't ask us to check your entire solution. See https://cs.stackexchange.com/tags/check-my-answer/info.
I think even better would be to use your attempt to solve the problem to diagnose where there are conceptual gaps or uncertainties in your understanding, and then ask a question about that concept -- hopefully, formulated in a way that might be useful to others. Don't ask us to check your solution to the exercise, but use the exercise to help you diagnose what you don't understand and then ask a question about that.
Also, please ask only one question per post. If there are two parts to the problem, don't ask us to check your solution to both, as those are two separate problems.
Finally, when quoting material originally written by others (such as a problem statement), please provide proper attribution for the original source: https://cs.stackexchange.com/help/referencing
