English
A lattice M in V over R with IsLattice structure over K has the R-rank of M equal to the K-rank of V.
Русский
У решётки M в V над R с структурой IsLattice над K ранг R-части M равен ранг K-V.
LaTeX
$$$\operatorname{rank}_R M = \operatorname{rank}_K V$$$
Lean4
/-- A finitely-generated `R`-submodule of `V` of rank at least the `K`-rank of `V`
is a lattice. -/
theorem of_rank_le [Module.Finite K V] [IsFractionRing R K] {M : Submodule R V} (hfg : M.FG)
(hr : Module.rank K V ≤ Module.rank R M) : IsLattice K M
where
fg := hfg
span_eq_top := by simpa using Submodule.span_range_eq_top_of_injective_of_rank_le M.injective_subtype hr