mathlib

58f8817e - feat(number_theory/fermat4): The n=4 case of fermat (#4720)

feat(number_theory/fermat4): The n=4 case of fermat (#4720) Fermat's last theorem for n=4. Co-authored-by: paulvanwamelen <30371019+paulvanwamelen@users.noreply.github.com> Co-authored-by: Johan Commelin <johan@commelin.net>