Documentation

Mathlib.LinearAlgebra.AffineSpace.AffineEquiv

Affine equivalences #

In this file we define AffineEquiv k P₁ P₂ (notation: P₁ ≃ᵃ[k] P₂) to be the type of affine equivalences between P₁ and P₂, i.e., equivalences such that both forward and inverse maps are affine maps.

We define the following equivalences:

We equip AffineEquiv k P P with a Group structure with multiplication corresponding to composition in AffineEquiv.group.

Tags #

affine space, affine equivalence

structure AffineEquiv (k : Type u_1) (P₁ : Type u_2) (P₂ : Type u_3) {V₁ : Type u_4} {V₂ : Type u_5} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] extends P₁ P₂ :
Type (max (max (max u_2 u_3) u_4) u_5)

An affine equivalence, denoted P₁ ≃ᵃ[k] P₂, is an equivalence between affine spaces such that both forward and inverse maps are affine.

We define it using an Equiv for the map and a LinearEquiv for the linear part in order to allow affine equivalences with good definitional equalities.

An affine equivalence, denoted P₁ ≃ᵃ[k] P₂, is an equivalence between affine spaces such that both forward and inverse maps are affine.

We define it using an Equiv for the map and a LinearEquiv for the linear part in order to allow affine equivalences with good definitional equalities.

Equations
  • One or more equations did not get rendered due to their size.
def AffineEquiv.toAffineMap {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
P₁ →ᵃ[k] P₂

Reinterpret an AffineEquiv as an AffineMap.

Equations
  • e = { toFun := e.toFun, linear := e.linear, map_vadd' := }
@[simp]
theorem AffineEquiv.toAffineMap_mk {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (f : P₁ P₂) (f' : V₁ ≃ₗ[k] V₂) (h : ∀ (p : P₁) (v : V₁), f (v +ᵥ p) = f' v +ᵥ f p) :
{ toEquiv := f, linear := f', map_vadd' := h } = { toFun := f, linear := f', map_vadd' := h }
@[simp]
theorem AffineEquiv.linear_toAffineMap {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
(↑e).linear = e.linear
theorem AffineEquiv.toAffineMap_injective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] :
@[simp]
theorem AffineEquiv.toAffineMap_inj {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {e e' : P₁ ≃ᵃ[k] P₂} :
e = e' e = e'
instance AffineEquiv.equivLike {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] :
EquivLike (P₁ ≃ᵃ[k] P₂) P₁ P₂
Equations
instance AffineEquiv.instCoeOutEquiv {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] :
CoeOut (P₁ ≃ᵃ[k] P₂) (P₁ P₂)
Equations
@[simp]
theorem AffineEquiv.map_vadd {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) (p : P₁) (v : V₁) :
e (v +ᵥ p) = e.linear v +ᵥ e p
@[simp]
theorem AffineEquiv.coe_toEquiv {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
e.toEquiv = e
instance AffineEquiv.instCoeAffineMap {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] :
Coe (P₁ ≃ᵃ[k] P₂) (P₁ →ᵃ[k] P₂)
Equations
@[simp]
theorem AffineEquiv.coe_toAffineMap {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
e = e
@[simp]
theorem AffineEquiv.coe_coe {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
e = e
@[simp]
theorem AffineEquiv.coe_linear {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
(↑e).linear = e.linear
theorem AffineEquiv.ext {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {e e' : P₁ ≃ᵃ[k] P₂} (h : ∀ (x : P₁), e x = e' x) :
e = e'
theorem AffineEquiv.coeFn_injective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] :
theorem AffineEquiv.coeFn_inj {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {e e' : P₁ ≃ᵃ[k] P₂} :
e = e' e = e'
theorem AffineEquiv.toEquiv_injective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] :
@[simp]
theorem AffineEquiv.toEquiv_inj {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {e e' : P₁ ≃ᵃ[k] P₂} :
e.toEquiv = e'.toEquiv e = e'
@[simp]
theorem AffineEquiv.coe_mk {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ P₂) (e' : V₁ ≃ₗ[k] V₂) (h : ∀ (p : P₁) (v : V₁), e (v +ᵥ p) = e' v +ᵥ e p) :
{ toEquiv := e, linear := e', map_vadd' := h } = e
def AffineEquiv.mk' {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁P₂) (e' : V₁ ≃ₗ[k] V₂) (p : P₁) (h : ∀ (p' : P₁), e p' = e' (p' -ᵥ p) +ᵥ e p) :
P₁ ≃ᵃ[k] P₂

Construct an affine equivalence by verifying the relation between the map and its linear part at one base point. Namely, this function takes a map e : P₁ → P₂, a linear equivalence e' : V₁ ≃ₗ[k] V₂, and a point p such that for any other point p' we have e p' = e' (p' -ᵥ p) +ᵥ e p.

Equations
  • AffineEquiv.mk' e e' p h = { toFun := e, invFun := fun (q' : P₂) => e'.symm (q' -ᵥ e p) +ᵥ p, left_inv := , right_inv := , linear := e', map_vadd' := }
@[simp]
theorem AffineEquiv.coe_mk' {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ P₂) (e' : V₁ ≃ₗ[k] V₂) (p : P₁) (h : ∀ (p' : P₁), e p' = e' (p' -ᵥ p) +ᵥ e p) :
(mk' (⇑e) e' p h) = e
@[simp]
theorem AffineEquiv.linear_mk' {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ P₂) (e' : V₁ ≃ₗ[k] V₂) (p : P₁) (h : ∀ (p' : P₁), e p' = e' (p' -ᵥ p) +ᵥ e p) :
(mk' (⇑e) e' p h).linear = e'
def AffineEquiv.symm {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
P₂ ≃ᵃ[k] P₁

Inverse of an affine equivalence as an affine equivalence.

Equations
@[simp]
theorem AffineEquiv.symm_toEquiv {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
@[simp]
theorem AffineEquiv.symm_linear {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
def AffineEquiv.Simps.apply {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
P₁P₂

See Note [custom simps projection]

Equations
def AffineEquiv.Simps.symm_apply {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
P₂P₁

See Note [custom simps projection]

Equations
theorem AffineEquiv.bijective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
theorem AffineEquiv.surjective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
theorem AffineEquiv.injective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
noncomputable def AffineEquiv.ofBijective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {φ : P₁ →ᵃ[k] P₂} (hφ : Function.Bijective φ) :
P₁ ≃ᵃ[k] P₂

Bijective affine maps are affine isomorphisms.

Equations
@[simp]
theorem AffineEquiv.linear_ofBijective {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {φ : P₁ →ᵃ[k] P₂} (hφ : Function.Bijective φ) :
@[simp]
theorem AffineEquiv.ofBijective_apply {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {φ : P₁ →ᵃ[k] P₂} (hφ : Function.Bijective φ) (a : P₁) :
(ofBijective ) a = φ a
theorem AffineEquiv.ofBijective.symm_eq {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] {φ : P₁ →ᵃ[k] P₂} (hφ : Function.Bijective φ) :
@[simp]
theorem AffineEquiv.range_eq {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
@[simp]
theorem AffineEquiv.apply_symm_apply {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) (p : P₂) :
e (e.symm p) = p
@[simp]
theorem AffineEquiv.symm_apply_apply {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) (p : P₁) :
e.symm (e p) = p
theorem AffineEquiv.apply_eq_iff_eq_symm_apply {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) {p₁ : P₁} {p₂ : P₂} :
e p₁ = p₂ p₁ = e.symm p₂
theorem AffineEquiv.apply_eq_iff_eq {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) {p₁ p₂ : P₁} :
e p₁ = e p₂ p₁ = p₂
@[simp]
theorem AffineEquiv.image_symm {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (f : P₁ ≃ᵃ[k] P₂) (s : Set P₂) :
f.symm '' s = f ⁻¹' s
@[simp]
theorem AffineEquiv.preimage_symm {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (f : P₁ ≃ᵃ[k] P₂) (s : Set P₁) :
f.symm ⁻¹' s = f '' s
def AffineEquiv.refl (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
P₁ ≃ᵃ[k] P₁

Identity map as an AffineEquiv.

Equations
@[simp]
theorem AffineEquiv.coe_refl (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
(refl k P₁) = id
@[simp]
theorem AffineEquiv.coe_refl_to_affineMap (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
(refl k P₁) = AffineMap.id k P₁
@[simp]
theorem AffineEquiv.refl_apply (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (x : P₁) :
(refl k P₁) x = x
@[simp]
theorem AffineEquiv.toEquiv_refl (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
(refl k P₁).toEquiv = Equiv.refl P₁
@[simp]
theorem AffineEquiv.linear_refl (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
(refl k P₁).linear = LinearEquiv.refl k V₁
@[simp]
theorem AffineEquiv.symm_refl (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
(refl k P₁).symm = refl k P₁
def AffineEquiv.trans {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {P₃ : Type u_4} {V₁ : Type u_6} {V₂ : Type u_7} {V₃ : Type u_8} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] [AddCommGroup V₃] [Module k V₃] [AddTorsor V₃ P₃] (e : P₁ ≃ᵃ[k] P₂) (e' : P₂ ≃ᵃ[k] P₃) :
P₁ ≃ᵃ[k] P₃

Composition of two AffineEquivalences, applied left to right.

Equations
@[simp]
theorem AffineEquiv.coe_trans {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {P₃ : Type u_4} {V₁ : Type u_6} {V₂ : Type u_7} {V₃ : Type u_8} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] [AddCommGroup V₃] [Module k V₃] [AddTorsor V₃ P₃] (e : P₁ ≃ᵃ[k] P₂) (e' : P₂ ≃ᵃ[k] P₃) :
(e.trans e') = e' e
@[simp]
theorem AffineEquiv.coe_trans_to_affineMap {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {P₃ : Type u_4} {V₁ : Type u_6} {V₂ : Type u_7} {V₃ : Type u_8} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] [AddCommGroup V₃] [Module k V₃] [AddTorsor V₃ P₃] (e : P₁ ≃ᵃ[k] P₂) (e' : P₂ ≃ᵃ[k] P₃) :
(e.trans e') = (↑e').comp e
@[simp]
theorem AffineEquiv.trans_apply {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {P₃ : Type u_4} {V₁ : Type u_6} {V₂ : Type u_7} {V₃ : Type u_8} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] [AddCommGroup V₃] [Module k V₃] [AddTorsor V₃ P₃] (e : P₁ ≃ᵃ[k] P₂) (e' : P₂ ≃ᵃ[k] P₃) (p : P₁) :
(e.trans e') p = e' (e p)
theorem AffineEquiv.trans_assoc {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {P₃ : Type u_4} {P₄ : Type u_5} {V₁ : Type u_6} {V₂ : Type u_7} {V₃ : Type u_8} {V₄ : Type u_9} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] [AddCommGroup V₃] [Module k V₃] [AddTorsor V₃ P₃] [AddCommGroup V₄] [Module k V₄] [AddTorsor V₄ P₄] (e₁ : P₁ ≃ᵃ[k] P₂) (e₂ : P₂ ≃ᵃ[k] P₃) (e₃ : P₃ ≃ᵃ[k] P₄) :
(e₁.trans e₂).trans e₃ = e₁.trans (e₂.trans e₃)
@[simp]
theorem AffineEquiv.trans_refl {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
e.trans (refl k P₂) = e
@[simp]
theorem AffineEquiv.refl_trans {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
(refl k P₁).trans e = e
@[simp]
theorem AffineEquiv.self_trans_symm {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
e.trans e.symm = refl k P₁
@[simp]
theorem AffineEquiv.symm_trans_self {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) :
e.symm.trans e = refl k P₂
@[simp]
theorem AffineEquiv.apply_lineMap {k : Type u_1} {P₁ : Type u_2} {P₂ : Type u_3} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [AddCommGroup V₂] [Module k V₂] [AddTorsor V₂ P₂] (e : P₁ ≃ᵃ[k] P₂) (a b : P₁) (c : k) :
e ((AffineMap.lineMap a b) c) = (AffineMap.lineMap (e a) (e b)) c
instance AffineEquiv.group {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
Group (P₁ ≃ᵃ[k] P₁)
Equations
theorem AffineEquiv.one_def {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
1 = refl k P₁
@[simp]
theorem AffineEquiv.coe_one {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
1 = id
theorem AffineEquiv.mul_def {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (e e' : P₁ ≃ᵃ[k] P₁) :
e * e' = e'.trans e
@[simp]
theorem AffineEquiv.coe_mul {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (e e' : P₁ ≃ᵃ[k] P₁) :
⇑(e * e') = e e'
theorem AffineEquiv.inv_def {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (e : P₁ ≃ᵃ[k] P₁) :
def AffineEquiv.linearHom {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
(P₁ ≃ᵃ[k] P₁) →* V₁ ≃ₗ[k] V₁

AffineEquiv.linear on automorphisms is a MonoidHom.

Equations
@[simp]
theorem AffineEquiv.linearHom_apply {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (self : P₁ ≃ᵃ[k] P₁) :
linearHom self = self.linear
def AffineEquiv.equivUnitsAffineMap {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
(P₁ ≃ᵃ[k] P₁) ≃* (P₁ →ᵃ[k] P₁)ˣ

The group of AffineEquivs are equivalent to the group of units of AffineMap.

This is the affine version of LinearMap.GeneralLinearGroup.generalLinearEquiv.

Equations
  • One or more equations did not get rendered due to their size.
@[simp]
theorem AffineEquiv.val_inv_equivUnitsAffineMap_apply {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (e : P₁ ≃ᵃ[k] P₁) :
@[simp]
theorem AffineEquiv.val_equivUnitsAffineMap_apply {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (e : P₁ ≃ᵃ[k] P₁) :
@[simp]
theorem AffineEquiv.equivUnitsAffineMap_symm_apply_apply {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (u : (P₁ →ᵃ[k] P₁)ˣ) (a : P₁) :
@[simp]
theorem AffineEquiv.equivUnitsAffineMap_symm_apply_toFun {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (u : (P₁ →ᵃ[k] P₁)ˣ) (a : P₁) :
@[simp]
theorem AffineEquiv.equivUnitsAffineMap_symm_apply_invFun {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (u : (P₁ →ᵃ[k] P₁)ˣ) (a : P₁) :
@[simp]
theorem AffineEquiv.equivUnitsAffineMap_symm_apply_symm_apply {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (u : (P₁ →ᵃ[k] P₁)ˣ) (a : P₁) :
def AffineEquiv.vaddConst (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (b : P₁) :
V₁ ≃ᵃ[k] P₁

The map v ↦ v +ᵥ b as an affine equivalence between a module V and an affine space P with tangent space V.

Equations
@[simp]
theorem AffineEquiv.vaddConst_apply (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (b : P₁) (v : V₁) :
(vaddConst k b) v = v +ᵥ b
@[simp]
theorem AffineEquiv.linear_vaddConst (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (b : P₁) :
@[simp]
theorem AffineEquiv.vaddConst_symm_apply (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (b p' : P₁) :
(vaddConst k b).symm p' = p' -ᵥ b
def AffineEquiv.constVSub (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (p : P₁) :
P₁ ≃ᵃ[k] V₁

p' ↦ p -ᵥ p' as an equivalence.

Equations
@[simp]
theorem AffineEquiv.coe_constVSub (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (p : P₁) :
(constVSub k p) = fun (x : P₁) => p -ᵥ x
@[simp]
theorem AffineEquiv.coe_constVSub_symm (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (p : P₁) :
(constVSub k p).symm = fun (v : V₁) => -v +ᵥ p
def AffineEquiv.constVAdd (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v : V₁) :
P₁ ≃ᵃ[k] P₁

The map p ↦ v +ᵥ p as an affine automorphism of an affine space.

Note that there is no need for an AffineMap.constVAdd as it is always an equivalence. This is roughly to DistribMulAction.toLinearEquiv as +ᵥ is to .

Equations
@[simp]
theorem AffineEquiv.linear_constVAdd (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v : V₁) :
@[simp]
theorem AffineEquiv.constVAdd_apply (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v : V₁) (x✝ : P₁) :
(constVAdd k P₁ v) x✝ = v +ᵥ x✝
@[simp]
theorem AffineEquiv.constVAdd_zero (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
constVAdd k P₁ 0 = refl k P₁
@[simp]
theorem AffineEquiv.constVAdd_add (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v w : V₁) :
constVAdd k P₁ (v + w) = (constVAdd k P₁ w).trans (constVAdd k P₁ v)
@[simp]
theorem AffineEquiv.constVAdd_symm (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v : V₁) :
(constVAdd k P₁ v).symm = constVAdd k P₁ (-v)
def AffineEquiv.constVAddHom (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] :
Multiplicative V₁ →* P₁ ≃ᵃ[k] P₁

A more bundled version of AffineEquiv.constVAdd.

Equations
@[simp]
theorem AffineEquiv.constVAddHom_apply (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v : Multiplicative V₁) :
theorem AffineEquiv.constVAdd_nsmul (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (n : ) (v : V₁) :
constVAdd k P₁ (n v) = constVAdd k P₁ v ^ n
theorem AffineEquiv.constVAdd_zsmul (k : Type u_1) (P₁ : Type u_2) {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (z : ) (v : V₁) :
constVAdd k P₁ (z v) = constVAdd k P₁ v ^ z
def AffineEquiv.homothetyUnitsMulHom {R : Type u_10} {V : Type u_11} {P : Type u_12} [CommRing R] [AddCommGroup V] [Module R V] [AddTorsor V P] (p : P) :

Fixing a point in affine space, homothety about this point gives a group homomorphism from (the centre of) the units of the scalars into the group of affine equivalences.

Equations
@[simp]
theorem AffineEquiv.coe_homothetyUnitsMulHom_apply {R : Type u_10} {V : Type u_11} {P : Type u_12} [CommRing R] [AddCommGroup V] [Module R V] [AddTorsor V P] (p : P) (t : Rˣ) :
@[simp]
theorem AffineEquiv.coe_homothetyUnitsMulHom_apply_symm {R : Type u_10} {V : Type u_11} {P : Type u_12} [CommRing R] [AddCommGroup V] [Module R V] [AddTorsor V P] (p : P) (t : Rˣ) :
def AffineEquiv.pointReflection (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (x : P₁) :
P₁ ≃ᵃ[k] P₁

Point reflection in x as a permutation.

Equations
theorem AffineEquiv.pointReflection_apply (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (x y : P₁) :
(pointReflection k x) y = (x -ᵥ y) +ᵥ x
@[simp]
theorem AffineEquiv.pointReflection_symm (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (x : P₁) :
@[simp]
theorem AffineEquiv.toEquiv_pointReflection (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (x : P₁) :
@[simp]
theorem AffineEquiv.pointReflection_self (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (x : P₁) :
(pointReflection k x) x = x
theorem AffineEquiv.pointReflection_involutive (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (x : P₁) :
theorem AffineEquiv.pointReflection_fixed_iff_of_injective_two_nsmul (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] {x y : P₁} (h : Function.Injective fun (x : V₁) => 2 x) :
(pointReflection k x) y = y y = x

x is the only fixed point of pointReflection x. This lemma requires x + x = y + y ↔ x = y. There is no typeclass to use here, so we add it as an explicit argument.

@[deprecated AffineEquiv.pointReflection_fixed_iff_of_injective_two_nsmul (since := "2024-11-18")]
theorem AffineEquiv.pointReflection_fixed_iff_of_injective_bit0 (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] {x y : P₁} (h : Function.Injective fun (x : V₁) => 2 x) :
(pointReflection k x) y = y y = x

Alias of AffineEquiv.pointReflection_fixed_iff_of_injective_two_nsmul.


x is the only fixed point of pointReflection x. This lemma requires x + x = y + y ↔ x = y. There is no typeclass to use here, so we add it as an explicit argument.

theorem AffineEquiv.injective_pointReflection_left_of_injective_two_nsmul (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (h : Function.Injective fun (x : V₁) => 2 x) (y : P₁) :
Function.Injective fun (x : P₁) => (pointReflection k x) y
@[deprecated AffineEquiv.injective_pointReflection_left_of_injective_two_nsmul (since := "2024-11-18")]
theorem AffineEquiv.injective_pointReflection_left_of_injective_bit0 (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (h : Function.Injective fun (x : V₁) => 2 x) (y : P₁) :
Function.Injective fun (x : P₁) => (pointReflection k x) y

Alias of AffineEquiv.injective_pointReflection_left_of_injective_two_nsmul.

theorem AffineEquiv.injective_pointReflection_left_of_module (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [Invertible 2] (y : P₁) :
Function.Injective fun (x : P₁) => (pointReflection k x) y
theorem AffineEquiv.pointReflection_fixed_iff_of_module (k : Type u_1) {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] [Invertible 2] {x y : P₁} :
(pointReflection k x) y = y y = x
def LinearEquiv.toAffineEquiv {k : Type u_1} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddCommGroup V₂] [Module k V₂] (e : V₁ ≃ₗ[k] V₂) :
V₁ ≃ᵃ[k] V₂

Interpret a linear equivalence between modules as an affine equivalence.

Equations
@[simp]
theorem LinearEquiv.coe_toAffineEquiv {k : Type u_1} {V₁ : Type u_6} {V₂ : Type u_7} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddCommGroup V₂] [Module k V₂] (e : V₁ ≃ₗ[k] V₂) :
e.toAffineEquiv = e
theorem AffineMap.lineMap_vadd {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v v' : V₁) (p : P₁) (c : k) :
(lineMap v v') c +ᵥ p = (lineMap (v +ᵥ p) (v' +ᵥ p)) c
theorem AffineMap.lineMap_vsub {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (p₁ p₂ p₃ : P₁) (c : k) :
(lineMap p₁ p₂) c -ᵥ p₃ = (lineMap (p₁ -ᵥ p₃) (p₂ -ᵥ p₃)) c
theorem AffineMap.vsub_lineMap {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (p₁ p₂ p₃ : P₁) (c : k) :
p₁ -ᵥ (lineMap p₂ p₃) c = (lineMap (p₁ -ᵥ p₂) (p₁ -ᵥ p₃)) c
theorem AffineMap.vadd_lineMap {k : Type u_1} {P₁ : Type u_2} {V₁ : Type u_6} [Ring k] [AddCommGroup V₁] [Module k V₁] [AddTorsor V₁ P₁] (v : V₁) (p₁ p₂ : P₁) (c : k) :
v +ᵥ (lineMap p₁ p₂) c = (lineMap (v +ᵥ p₁) (v +ᵥ p₂)) c
theorem AffineMap.homothety_neg_one_apply {P₁ : Type u_2} {V₁ : Type u_6} [AddCommGroup V₁] [AddTorsor V₁ P₁] {R' : Type u_10} [CommRing R'] [Module R' V₁] (c p : P₁) :