mathlib3

11e1cc36 - feat(data/equiv/basic): Add `fin_succ_above_equiv` (#5145)

feat(data/equiv/basic): Add `fin_succ_above_equiv` (#5145) Co-authored-by: Yakov Pechersky <ffxen158@gmail.com> Co-authored-by: Yakov Pechersky <pechersky@users.noreply.github.com>