http://3cbzkrvakrpetjjppdwzbzqrlkmzatjs7jbyazap5gwutj32gcltjpqd.onion
I had drafted a blog post for the official Lean FRO blog back then, but forgot about it, and with the Lean FRO blog discontinued, I’ll just publish it here, better late than never. With the partial_fixpoint mechanism we can model possibly partial functions (so those returning an Option ) without an explicit termination proof, and still prove facts about them.