English
For e12: M1 ≃ₛₗ[σ12] M2 and g ∈ GeneralLinearGroup R1 M1, the image under congrLinearEquiv is the element of GeneralLinearGroup R2 M2 corresponding to the linear conjugation e12.symm.trans (g.toLinearEquiv.trans e12).
Русский
Для e12: M1 ≃ₛₗ[σ12] M2 и g ∈ GeneralLinearGroup R1 M1 образ под congrLinearEquiv есть элемент в GeneralLinearGroup R2 M2, соответствующий линейному сопряжению e12.symm.trans (g.toLinearEquiv.trans e12).
LaTeX
$$$ congrLinearEquiv e_{12} \, g = \text{ofLinearEquiv}(e_{12}^{\mathsf{symm}} \;\circ\; g^{\;toLinearEquiv} \;\circ\; e_{12}). $$$
Lean4
@[simp]
theorem congrLinearEquiv_apply (e₁₂ : M₁ ≃ₛₗ[σ₁₂] M₂) (g : GeneralLinearGroup R₁ M₁) :
congrLinearEquiv e₁₂ g = ofLinearEquiv (e₁₂.symm.trans <| g.toLinearEquiv.trans e₁₂) :=
rfl