Composition of matrices

This file shows that Mₙ(Mₘ(R)) ≃ Mₙₘ(R), Mₙ(Rᵒᵖ) ≃ₐ[K] Mₙ(R)ᵒᵖ and also different levels of equivalence when R is an AddCommMonoid, Semiring, and Algebra over a CommSemiring K.

Main results

• Matrix.comp is an equivalence between Matrix I J (Matrix K L R) and I × K by J × L matrices.
• Matrix.swap is an equivalence between (I × J) by (K × L) matrices and J × I by L × K matrices.

@[simp]

theorem Matrix.comp_apply (I : Type u_1) (J : Type u_2) (K : Type u_3) (L : Type u_4) (R : Type u_5) (m : Matrix I J (Matrix K L R)) (ik : I × K) (jl : J × L) : (Matrix.comp I J K L R) m ik jl = m ik.1 jl.1 ik.2 jl.2

@[simp]

theorem Matrix.comp_symm_apply (I : Type u_1) (J : Type u_2) (K : Type u_3) (L : Type u_4) (R : Type u_5) (n : Matrix (I × K) (J × L) R) (i : I) (j : J) (k : K) (l : L) : (Matrix.comp I J K L R).symm n i j k l = n (i, k) (j, l)

def Matrix.comp (I : Type u_1) (J : Type u_2) (K : Type u_3) (L : Type u_4) (R : Type u_5) : Matrix I J (Matrix K L R) ≃ Matrix (I × K) (J × L) R

I by J matrix where each entry is a K by L matrix is equivalent to I × K by J × L matrix

Equations

• One or more equations did not get rendered due to their size.

@[simp]

theorem Matrix.compAddEquiv_apply (I : Type u_1) (J : Type u_2) (K : Type u_3) (L : Type u_4) (R : Type u_5) [AddCommMonoid R] (m : Matrix I J (Matrix K L R)) (ik : I × K) (jl : J × L) : (Matrix.compAddEquiv I J K L R) m ik jl = m ik.1 jl.1 ik.2 jl.2

@[simp]

theorem Matrix.compAddEquiv_symm_apply (I : Type u_1) (J : Type u_2) (K : Type u_3) (L : Type u_4) (R : Type u_5) [AddCommMonoid R] (n : Matrix (I × K) (J × L) R) (i : I) (j : J) (k : K) (l : L) : (Matrix.compAddEquiv I J K L R).symm n i j k l = n (i, k) (j, l)

def Matrix.compAddEquiv (I : Type u_1) (J : Type u_2) (K : Type u_3) (L : Type u_4) (R : Type u_5) [AddCommMonoid R] : Matrix I J (Matrix K L R) ≃+ Matrix (I × K) (J × L) R

Matrix.comp as AddEquiv

Equations

• Matrix.compAddEquiv I J K L R = let __spread.0 := Matrix.comp I J K L R; { toEquiv := __spread.0, map_add' := ⋯ }

@[simp]

theorem Matrix.compRingEquiv_apply (I : Type u_1) (J : Type u_2) (R : Type u_5) [Semiring R] [Fintype I] [Fintype J] (m : Matrix I I (Matrix J J R)) (ik : I × J) (jl : I × J) : (Matrix.compRingEquiv I J R) m ik jl = m ik.1 jl.1 ik.2 jl.2

@[simp]

theorem Matrix.compRingEquiv_symm_apply (I : Type u_1) (J : Type u_2) (R : Type u_5) [Semiring R] [Fintype I] [Fintype J] (n : Matrix (I × J) (I × J) R) (i : I) (j : I) (k : J) (l : J) : (Matrix.compRingEquiv I J R).symm n i j k l = n (i, k) (j, l)

def Matrix.compRingEquiv (I : Type u_1) (J : Type u_2) (R : Type u_5) [Semiring R] [Fintype I] [Fintype J] : Matrix I I (Matrix J J R) ≃+* Matrix (I × J) (I × J) R

Matrix.comp as RingEquiv

Equations

• Matrix.compRingEquiv I J R = let __spread.0 := Matrix.compAddEquiv I I J J R; { toEquiv := __spread.0.toEquiv, map_mul' := ⋯, map_add' := ⋯ }

@[simp]

theorem Matrix.compLinearEquiv_apply (I : Type u_1) (J : Type u_2) (L : Type u_4) (R : Type u_5) (K : Type u_6) [CommSemiring K] [AddCommMonoid R] [Module K R] : ∀ (a : Matrix I J (Matrix K L R)), (Matrix.compLinearEquiv I J L R K) a = (Matrix.compAddEquiv I J K L R) a

@[simp]

theorem Matrix.compLinearEquiv_symm_apply (I : Type u_1) (J : Type u_2) (L : Type u_4) (R : Type u_5) (K : Type u_6) [CommSemiring K] [AddCommMonoid R] [Module K R] : ∀ (a : Matrix (I × K) (J × L) R), (Matrix.compLinearEquiv I J L R K).symm a = (Matrix.compAddEquiv I J K L R).symm a

def Matrix.compLinearEquiv (I : Type u_1) (J : Type u_2) (L : Type u_4) (R : Type u_5) (K : Type u_6) [CommSemiring K] [AddCommMonoid R] [Module K R] : Matrix I J (Matrix K L R) ≃ₗ[K] Matrix (I × K) (J × L) R

Matrix.comp as LinearEquiv

Equations

• One or more equations did not get rendered due to their size.

@[simp]

theorem Matrix.compAlgEquiv_apply (I : Type u_1) (J : Type u_2) (R : Type u_5) (K : Type u_6) [CommSemiring K] [Semiring R] [Fintype I] [Fintype J] [Algebra K R] [DecidableEq I] [DecidableEq J] (m : Matrix I I (Matrix J J R)) (ik : I × J) (jl : I × J) : (Matrix.compAlgEquiv I J R K) m ik jl = m ik.1 jl.1 ik.2 jl.2

@[simp]

theorem Matrix.compAlgEquiv_symm_apply (I : Type u_1) (J : Type u_2) (R : Type u_5) (K : Type u_6) [CommSemiring K] [Semiring R] [Fintype I] [Fintype J] [Algebra K R] [DecidableEq I] [DecidableEq J] (n : Matrix (I × J) (I × J) R) (i : I) (j : I) (k : J) (l : J) : (Matrix.compAlgEquiv I J R K).symm n i j k l = n (i, k) (j, l)

def Matrix.compAlgEquiv (I : Type u_1) (J : Type u_2) (R : Type u_5) (K : Type u_6) [CommSemiring K] [Semiring R] [Fintype I] [Fintype J] [Algebra K R] [DecidableEq I] [DecidableEq J] : Matrix I I (Matrix J J R) ≃ₐ[K] Matrix (I × J) (I × J) R

Matrix.comp as AlgEquiv

Equations

• Matrix.compAlgEquiv I J R K = let __spread.0 := Matrix.compRingEquiv I J R; { toEquiv := __spread.0.toEquiv, map_mul' := ⋯, map_add' := ⋯, commutes' := ⋯ }