English
Unfold lemma for detAux: detAux equals the determinant obtained from a chosen basis.
Русский
Развертывающее лемму для detAux: detAux равенDeterminant для выбранного базиса.
LaTeX
$$detAux_def' (b : Trunc (Module.Basis ι A M)) (f : M →ₗ[A] M) : LinearMap.detAux (Trunc.mk b) f = Matrix.det (LinearMap.toMatrix b b f)$$
Lean4
theorem detAux_def'' {ι' : Type*} [Fintype ι'] [DecidableEq ι'] (tb : Trunc <| Basis ι A M) (b' : Basis ι' A M)
(f : M →ₗ[A] M) : LinearMap.detAux tb f = Matrix.det (LinearMap.toMatrix b' b' f) := by
induction tb using Trunc.induction_on with
| h b => rw [detAux_def', det_toMatrix_eq_det_toMatrix b b']