Commit 2025-02-17 17:27 9d1a5226
View on Github →chore(Data/Fintype): split Data/Fintype/Basic.lean (#21831)
This PR splits Data.Fintype.Basic into the following files:
Data.Fintype.Defs: definition ofFintypeandFinset.univData.Finset.BooleanAlgebra: showsFinsetis a boolean algebra (withFinset.univas top element)Data.Fintype.Basic: instances forFintypeon most basic types such as products and pi typesData.Fintype.Group: finiteness and additive/multiplicative structuresData.Fintype.Inv: computably choosing existential witnesses and constructing inverse functionsData.Fintype.OfMap: constructors forFintypegiven maps from/to finite typesData.Fintype.Sets: equivalence betweenSetandFinseton finite types A particular goal is to avoid importing the algebra hierarchy while working on finiteness and eventually into measure theory.