Commit 2025-03-31 13:41 82533ad0

feat(Matroid/Rank): ENat-valued matroid rank (#23377) We define the ENat-valued rank M.eRank of a matroid M, and also the function M.eRk which gives the rank of each set in M. We give basic API for these functions, including submodularity. These are analogous to the existing cardinal-valued Matroid.cRank and Matroid.cRk, but are much nicer, because the bases of a matroid are always equicardinal in the sense of ENat-valued cardinality but not Cardinal-valued.