Commit 2021-11-08 16:03 1519cd77
View on Github →chore(set_theory/cardinal): more simp, fix LHS/RHS (#10212)
While coe (fintype.card α) is a larger expression than #α, it allows us to compute the cardinality of a finite type provided that we have a simp lemma for fintype.card α. It also plays well with lemmas about coercions from nat and cardinal.lift.
- rename
cardinal.fintype_cardtocardinal.mk_fintype, make it a@[simp]lemma; - deduce other cases (
bool,Prop,unique,is_empty) from it; - rename
cardinal.finset_cardtocardinal.mk_finset, swap LHS/RHS; - rename
ordinal.fintype_cardtoordinal.type_fintype.