I tested it several times, new chats never got this right at first. I tried at least 6 times. I was experimenting and found that GPT4 couldn't be fooled by faul

I tested it several times, new chats never got this right at first. I tried at least 6 times. I was experimenting and found that GPT4 couldn't be fooled by faulty proofs. Only a valid proof could change its mind. Now it seems to know this mathematical property from first prompt though.