My goal is to get a new claim environment which automatically numbers. This is fine - I can make a counter, define a claim environment and claimproof environment which number automatically, and this is all fine.
However, I would like the numbering to start at one for each proof, which means I need to reset the counter at the beginning of each proof. I can do this by defining a new environment, "myproof" or so on, which is a wrapper for proof, but I would like it to automatically work on existing LaTeX code.
So how can I "redefine" the proof environment without rewriting the proof environment from scratch?