English
Under the same hypotheses as above, the finite cardinality of AlgHom K S L equals pb.dim.
Русский
При тех же предположениях число гомоморфизмов по K от S в L равно pb.dim.
LaTeX
$$$|S \\to_K L| = pb.dim$$$
Lean4
theorem card_of_powerBasis (pb : PowerBasis K S) (h_sep : IsSeparable K pb.gen)
(h_splits : (minpoly K pb.gen).Splits (algebraMap K L)) :
@Fintype.card (S →ₐ[K] L) (PowerBasis.AlgHom.fintype pb) = pb.dim := by
classical rw [Fintype.card_eq_nat_card, AlgHom.natCard_of_powerBasis pb h_sep h_splits]