3 ms·Fermat did several proofs by infinite descent without bringing set theory into it ;-)by phkahler 4y agoFermat did several proofs by infinite descent without bringing set theory into it ;-)henrydark 4y agoActually he did use set theory, but there wasn't enough space in the marginsbombcar 4y agoThere's a large body of math that can be proved simply, or proved complexly using set theory ;)