Maths proof custom "checking" environment

Often in a proof we have a list of things we need to check that would be wrong to call different cases. For example if we want to check that $R$ is a ring, it would be very morally wrong to have a separate "case" for checking each ring axiom. However it might be handy to have something like this;

There are lots of answers on this site on how to make similar stuff that is automatically numbered, but I want to be able make an environment where I can put in a custom ‘title’.