English
Under finiteness and basis assumptions, the rank equals the natTrailingDegree of the characteristic polynomial of the endomorphism associated to φ.
Русский
При конечности и заданном базисе ранг равен natTrailingDegree характеристического многочлена соответствующего эндоморфизма.
LaTeX
$$rank R L M = (polyCharpoly φ b).natTrailingDegree$$
Lean4
theorem rank_eq_natTrailingDegree [Nontrivial R] [DecidableEq ι] : rank R L M = (polyCharpoly φ b).natTrailingDegree :=
by apply nilRank_eq_polyCharpoly_natTrailingDegree