Commit 2024-05-21 16:45 27b3df77
View on Github →feat: SuccOrder and recursion principle on well-ordered type (#11290)
Order/SuccPred/Basic.lean: add SuccOrder.ofLinearWellFoundedLT
, which puts a SuccOrder on an arbitrary well-ordered type. Also add the dual, PredOrder
version. Add missing pred
lemmas corresponding to existing succ
lemmas.
Order/SuccPred/Limit.lean: add SuccOrder.limitRecOn
generalizing Ordinal.limitRecOn
to allow definition by transfinite recursion on an arbitrary well-ordered type. (It turns out a partial well-founded order is enough.)
SetTheory/Ordinal/Arithmetic.lean: refactor Ordinal.limitRecOn
to use SuccOrder.limitRecOn
.
SetTheory/Cardinal/Ordinal.lean: add a lemma saying that the initial ordinal of an infinite cardinal is a NoMaxOrder.
SetTheory/Ordinal/Basic.lean: add mk_Iio_ord_out_α
, a restatement of card_typein_out_lt
.