mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
I : Type u_3
e : I → R
he : OrthogonalIdempotents e
i : I
s : Finset I
h : i ∈ s
⊢ e i * ∑ j ∈ s, e j = e i

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
I : Type u_3
e : I → R
he : OrthogonalIdempotents e
i : I
s : Finset I
h : i ∉ s
⊢ e i * ∑ j ∈ s, e j = 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Semiring R
inst✝ : Semiring S
f : R →+* S
I : Type u_3
e : I → R
he : OrthogonalIdempotents e
⊢ OrthogonalIdempotents (⇑f ∘ e)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Semiring R
inst✝ : Semiring S
f : R →+* S
I : Type u_3
e : I → R
hf : Function.Injective ⇑f
⊢ OrthogonalIdempotents (⇑f ∘ e) ↔ OrthogonalIdempotents e

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
I : Type u_3
e : I → R
he : OrthogonalIdempotents e
J : Type u_4
i : J ↪ I
⊢ OrthogonalIdempotents (e ∘ ⇑i)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Finiteness.Prod

Goal state before:
pp: R : Type u_1
M : Type u_2
inst✝⁴ : Semiring R
inst✝³ : AddCommMonoid M
inst✝² : Module R M
P : Type u_3
inst✝¹ : AddCommMonoid P
inst✝ : Module R P
sb : Submodule R M
sc : Submodule R P
hsb : sb.FG
hsc : sc.FG
tb : Set M
htb : tb.Finite ∧ span R tb = sb
tc : Set P
htc : tc.Finite ∧ span R tc = sc
⊢ span R (⇑(LinearMap.inl R M P) '' tb ∪ ⇑(LinearMap.inr R M P) '' tc) = sb.prod sc

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Finiteness.Prod

Goal state before:
pp: R : Type u_1
M : Type u_2
N : Type u_3
inst✝⁴ : Semiring R
inst✝³ : AddCommMonoid M
inst✝² : Module R M
inst✝¹ : AddCommMonoid N
inst✝ : Module R N
hM : Module.Finite R M
hN : Module.Finite R N
⊢ ⊤.FG

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
A : Type u_2
M : Type uM
ι : Type uι
inst✝⁴ : CommSemiring R
inst✝³ : Semiring A
inst✝² : Algebra R A
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
b : Basis ι R M
a : A
m : M
⊢ (basisAux A b) (a ⊗ₜ[R] m) = a • Finsupp.mapRange ⇑(algebraMap R A) ⋯ (b.repr m)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
A : Type u_2
M : Type uM
ι : Type uι
inst✝⁴ : CommSemiring R
inst✝³ : Semiring A
inst✝² : Algebra R A
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
b : Basis ι R M
a : A
x : A ⊗[R] M
⊢ (basisAux A b) (a • 0) = a • (basisAux A b) 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
A : Type u_2
M : Type uM
ι : Type uι
inst✝⁴ : CommSemiring R
inst✝³ : Semiring A
inst✝² : Algebra R A
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
b : Basis ι R M
a : A
x✝ : A ⊗[R] M
x : A
y : M
⊢ (basisAux A b) (a • x ⊗ₜ[R] y) = a • (basisAux A b) (x ⊗ₜ[R] y)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
I : Type u_3
e : I → R
J : Type u_4
i : J ≃ I
⊢ OrthogonalIdempotents (e ∘ ⇑i) ↔ OrthogonalIdempotents e

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝¹ : Semiring R
I : Type u_3
e : I → R
inst✝ : Unique I
⊢ OrthogonalIdempotents e ↔ IsIdempotentElem (e default)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
A : Type u_2
M : Type uM
ι : Type uι
inst✝⁴ : CommSemiring R
inst✝³ : Semiring A
inst✝² : Algebra R A
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
b : Basis ι R M
a : A
x✝ x y : A ⊗[R] M
hx : (basisAux A b) (a • x) = a • (basisAux A b) x
hy : (basisAux A b) (a • y) = a • (basisAux A b) y
⊢ (basisAux A b) (a • (x + y)) = a • (basisAux A b) (x + y)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
A : Type u_2
M : Type uM
ι : Type uι
inst✝⁴ : CommSemiring R
inst✝³ : Semiring A
inst✝² : Algebra R A
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
b : Basis ι R M
a : A
i : ι
⊢ (basis A b).repr.symm (Finsupp.single i a) = a ⊗ₜ[R] b.repr.symm (Finsupp.single i 1)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
A : Type u_2
M : Type uM
ι : Type uι
inst✝⁴ : CommSemiring R
inst✝³ : Semiring A
inst✝² : Algebra R A
inst✝¹ : AddCommMonoid M
inst✝ : Module R M
b : Basis ι R M
a : A
i : ι
⊢ a • (basis A b) i = a ⊗ₜ[R] b i

Tactic:
by

Goal state after:
Module: Mathlib.Algebra.ContinuedFractions.Computation.Approximations

Goal state before:
pp: K : Type u_1
v : K
n : ℕ
inst✝³ : Field K
inst✝² : LinearOrder K
inst✝¹ : IsStrictOrderedRing K
inst✝ : FloorRing K
not_terminatedAt_n : ¬(of v).TerminatedAt n
g : GenContFract K := of v
nextConts : Pair K := g.contsAux (n + 2)
conts : Pair K := g.contsAux (n + 1)
conts_eq : conts = g.contsAux (n + 1)
pred_conts : Pair K := g.contsAux n
pred_conts_eq : pred_conts = g.contsAux n
gp : Pair K
s_nth_eq : g.s.get? n = some gp
gp_a_eq_one : gp.a = 1
nextConts_b_eq : nextConts.b = pred_conts.b + gp.b * conts.b
den : K := conts.b * (pred_conts.b + gp.b * conts.b)
ifp_succ_n : IntFractPair K
succ_nth_stream_eq : IntFractPair.stream v (n + 1) = some ifp_succ_n
ifp_succ_n_b_eq_gp_b : ↑ifp_succ_n.b = gp.b
ifp_n : IntFractPair K
stream_nth_eq : IntFractPair.stream v n = some ifp_n
stream_nth_fr_ne_zero : ifp_n.fr ≠ 0
if_of_eq_ifp_succ_n : IntFractPair.of ifp_n.fr⁻¹ = ifp_succ_n
den' : K := conts.b * (pred_conts.b + ifp_n.fr⁻¹ * conts.b)
nextConts_b_ineq : ↑(fib (n + 2)) ≤ pred_conts.b + gp.b * conts.b
conts_b_ineq : ↑(fib (n + 1)) ≤ conts.b
zero_lt_conts_b : 0 < conts.b
this : gp.b * conts.b ≤ ifp_n.fr⁻¹ * conts.b
⊢ den ≤ den'

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝¹ : Semiring R
I : Type u_3
e : I → R
he : OrthogonalIdempotents e
inst✝ : Fintype I
x : R
hx : IsIdempotentElem x
hx₁ : x * ∑ i, e i = 0
hx₂ : (∑ i, e i) * x = 0
i j : Option I
ne : i ≠ j
⊢ (fun x1 x2 ↦ x1.elim x e * x2.elim x e = 0) i j

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
M : Type uM
ι : Type uι
inst✝⁹ : CommSemiring R
inst✝⁸ : AddCommMonoid M
inst✝⁷ : Module R M
inst✝⁶ : Fintype ι
ι' : Type u_3
N : Type u_4
inst✝⁵ : Fintype ι'
inst✝⁴ : DecidableEq ι'
inst✝³ : AddCommMonoid N
inst✝² : Module R N
A : Type u_5
inst✝¹ : CommSemiring A
inst✝ : Algebra R A
b : Basis ι R M
b' : Basis ι' R N
ij : ι × ι'
⊢ baseChange A ((b'.linearMap b) ij) = ((basis A b').linearMap (basis A b)) ij

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.TensorProduct.Free

Goal state before:
pp: R : Type u_1
M₁ : Type u_2
M₂ : Type u_3
ι : Type u_4
ι₂ : Type u_5
A : Type u_6
inst✝⁹ : Fintype ι
inst✝⁸ : Finite ι₂
inst✝⁷ : DecidableEq ι
inst✝⁶ : CommSemiring R
inst✝⁵ : CommSemiring A
inst✝⁴ : Algebra R A
inst✝³ : AddCommMonoid M₁
inst✝² : Module R M₁
inst✝¹ : AddCommMonoid M₂
inst✝ : Module R M₂
f : M₁ →ₗ[R] M₂
b₁ : Basis ι R M₁
b₂ : Basis ι₂ R M₂
⊢ (toMatrix (basis A b₁) (basis A b₂)) (baseChange A f) = ((toMatrix b₁ b₂) f).map ⇑(algebraMap R A)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝¹ : Semiring R
I : Type u_3
e : I → R
inst✝ : Fintype I
ortho : Pairwise fun x1 x2 ↦ e x1 * e x2 = 0
i : I
complete : ∑ i_1, e i * e i_1 = e i * 1
x✝ : i ∉ Finset.univ
⊢ e i * e i = 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝¹ : Semiring R
I : Type u_3
e : I → R
inst✝ : Fintype I
⊢ CompleteOrthogonalIdempotents e ↔ (Pairwise fun x1 x2 ↦ e x1 * e x2 = 0) ∧ ∑ i, e i = 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
x y : R
⊢ CompleteOrthogonalIdempotents ![x, y] ↔ x * y = 0 ∧ y * x = 0 ∧ x + y = 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_4
inst✝ : CommSemiring R
x y : R
⊢ CompleteOrthogonalIdempotents ![x, y] ↔ x * y = 0 ∧ x + y = 1

Tactic:
by

Goal state after:
Module: Mathlib.Algebra.Ring.Action.ConjAct

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
⊢ ∀ (a : ConjAct Rˣ), a • 0 = 0

Tactic:
by

Goal state after:
Module: Mathlib.Algebra.Ring.Action.ConjAct

Goal state before:
pp: R : Type u_1
inst✝ : Semiring R
⊢ ∀ (a : ConjAct Rˣ) (x y : R), a • (x + y) = a • x + a • y

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝² : Semiring R
I : Type u_3
e : I → R
inst✝¹ : Fintype I
inst✝ : Unique I
⊢ CompleteOrthogonalIdempotents e ↔ e default = 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: I : Type u_4
inst✝² : Fintype I
inst✝¹ : DecidableEq I
R : I → Type u_5
inst✝ : (i : I) → Semiring (R i)
⊢ ∀ (i : I), IsIdempotentElem (Pi.single i 1)

Tactic:
by

Goal state after:
Module: Mathlib.Algebra.ContinuedFractions.Computation.Approximations

Goal state before:
pp: K : Type u_1
v : K
n : ℕ
inst✝³ : Field K
inst✝² : LinearOrder K
inst✝¹ : IsStrictOrderedRing K
inst✝ : FloorRing K
not_terminatedAt_n : ¬(of v).TerminatedAt n
g : GenContFract K := of v
nextConts : Pair K := g.contsAux (n + 2)
conts : Pair K := g.contsAux (n + 1)
conts_eq : conts = g.contsAux (n + 1)
pred_conts : Pair K := g.contsAux n
pred_conts_eq : pred_conts = g.contsAux n
gp : Pair K
s_nth_eq : g.s.get? n = some gp
gp_a_eq_one : gp.a = 1
nextConts_b_eq : nextConts.b = pred_conts.b + gp.b * conts.b
den : K := conts.b * (pred_conts.b + gp.b * conts.b)
ifp_succ_n : IntFractPair K
succ_nth_stream_eq : IntFractPair.stream v (n + 1) = some ifp_succ_n
ifp_succ_n_b_eq_gp_b : ↑ifp_succ_n.b = gp.b
ifp_n : IntFractPair K
stream_nth_eq : IntFractPair.stream v n = some ifp_n
stream_nth_fr_ne_zero : ifp_n.fr ≠ 0
if_of_eq_ifp_succ_n : IntFractPair.of ifp_n.fr⁻¹ = ifp_succ_n
den' : K := conts.b * (pred_conts.b + ifp_n.fr⁻¹ * conts.b)
nextConts_b_ineq : ↑(fib (n + 2)) ≤ pred_conts.b + gp.b * conts.b
conts_b_ineq : ↑(fib (n + 1)) ≤ conts.b
zero_lt_conts_b : 0 < conts.b
this : ↑ifp_succ_n.b * conts.b ≤ ifp_n.fr⁻¹ * conts.b
⊢ gp.b * conts.b ≤ ifp_n.fr⁻¹ * conts.b

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
W : Type u_3
inst✝⁶ : Semifield K
inst✝⁵ : AddCommMonoid V
inst✝⁴ : Module K V
inst✝³ : Projective K V
inst✝² : AddCommMonoid W
inst✝¹ : Module K W
inst✝ : Projective K W
f : End K V ≃ₐ[K] End K W
hV : Nontrivial V
u : V
hu : u ≠ 0
v : Dual K V
huv : v u ≠ 0
⊢ ∃ z, ¬(f (smulRight v u)) z = 0 z

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: I : Type u_4
inst✝² : Fintype I
inst✝¹ : DecidableEq I
R : I → Type u_5
inst✝ : (i : I) → Semiring (R i)
⊢ CompleteOrthogonalIdempotents fun x ↦ Pi.single x 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : Semiring R
inst✝¹ : Semiring S
f : R →+* S
I : Type u_3
e : I → R
inst✝ : Fintype I
he : CompleteOrthogonalIdempotents e
⊢ ∑ i, (⇑f ∘ e) i = 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : Semiring R
inst✝¹ : Semiring S
f : R →+* S
I : Type u_3
e : I → R
inst✝ : Fintype I
hf : Function.Injective ⇑f
⊢ CompleteOrthogonalIdempotents (⇑f ∘ e) ↔ CompleteOrthogonalIdempotents e

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝² : Semiring R
I : Type u_3
e : I → R
inst✝¹ : Fintype I
J : Type u_4
inst✝ : Fintype J
i : J ≃ I
⊢ CompleteOrthogonalIdempotents (e ∘ ⇑i) ↔ CompleteOrthogonalIdempotents e

Tactic:
by

Goal state after:
Module: Mathlib.Algebra.ContinuedFractions.Computation.Approximations

Goal state before:
pp: K : Type u_1
v : K
n : ℕ
inst✝³ : Field K
inst✝² : LinearOrder K
inst✝¹ : IsStrictOrderedRing K
inst✝ : FloorRing K
not_terminatedAt_n : ¬(of v).TerminatedAt n
⊢ |v - (of v).convs n| ≤ 1 / ((of v).dens n * (of v).dens (n + 1))

Tactic:
by

Goal state after:
Module: Mathlib.Algebra.ContinuedFractions.Computation.Approximations

Goal state before:
pp: K : Type u_1
v : K
n : ℕ
inst✝³ : Field K
inst✝² : LinearOrder K
inst✝¹ : IsStrictOrderedRing K
inst✝ : FloorRing K
b : K
nth_partDen_eq : (of v).partDens.get? n = some b
⊢ ¬(of v).TerminatedAt n

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
W : Type u_3
inst✝⁶ : Semifield K
inst✝⁵ : AddCommMonoid V
inst✝⁴ : Module K V
inst✝³ : Projective K V
inst✝² : AddCommMonoid W
inst✝¹ : Module K W
inst✝ : Projective K W
f : End K V ≃ₐ[K] End K W
hV : Nontrivial V
u : V
hu : u ≠ 0
v : Dual K V
huv : v u ≠ 0
z : W
hz : ¬(f (smulRight v u)) z = 0 z
T : V →ₗ[K] W := applyₗ z ∘ₗ f.toLinearMap ∘ₗ smulRightₗ v
hT : ∀ (x : V), T x = (f (smulRight v x)) z
A : End K V
x : V
⊢ T (A x) = (f A) (T x)

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
W : Type u_3
inst✝⁶ : Semifield K
inst✝⁵ : AddCommMonoid V
inst✝⁴ : Module K V
inst✝³ : Projective K V
inst✝² : AddCommMonoid W
inst✝¹ : Module K W
inst✝ : Projective K W
f : End K V ≃ₐ[K] End K W
hV : Nontrivial V
u : V
hu : u ≠ 0
v : Dual K V
huv : v u ≠ 0
z : W
hz : ¬(f (smulRight v u)) z = 0 z
T : V →ₗ[K] W := applyₗ z ∘ₗ f.toLinearMap ∘ₗ smulRightₗ v
hT : ∀ (x : V), T x = (f (smulRight v x)) z
this : ∀ (A : End K V) (x : V), T (A x) = (f A) (T x)
w : W
d : Dual K W
hd : d ((f (smulRight v u)) z) = 1
⊢ T ((f.symm (smulRight d w)) u) = w

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
W : Type u_3
inst✝⁶ : Semifield K
inst✝⁵ : AddCommMonoid V
inst✝⁴ : Module K V
inst✝³ : Projective K V
inst✝² : AddCommMonoid W
inst✝¹ : Module K W
inst✝ : Projective K W
f : End K V ≃ₐ[K] End K W
hV : Nontrivial V
u : V
hu : u ≠ 0
v : Dual K V
huv : v u ≠ 0
z : W
hz : ¬(f (smulRight v u)) z = 0 z
T : V →ₗ[K] W := applyₗ z ∘ₗ f.toLinearMap ∘ₗ smulRightₗ v
hT : ∀ (x : V), T x = (f (smulRight v x)) z
this : ∀ (A : End K V) (x : V), T (A x) = (f A) (T x)
w : W
⊢ ∃ a, T a = w

Tactic:
by

Goal state after:
Module: Mathlib.Algebra.ContinuedFractions.Computation.Approximations

Goal state before:
pp: K : Type u_1
v : K
n : ℕ
inst✝³ : Field K
inst✝² : LinearOrder K
inst✝¹ : IsStrictOrderedRing K
inst✝ : FloorRing K
b : K
nth_partDen_eq : (of v).partDens.get? n = some b
⊢ |v - (of v).convs n| ≤ 1 / (b * (of v).dens n * (of v).dens n)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Ring R
x : R
n : ℕ
hx : (x - x ^ 2) ^ n = 0
⊢ (x - x ^ 2) ^ n ∣ 1 - (1 - x ^ n) ^ n - (1 - (1 - x ^ n) ^ n) ^ 2

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
W : Type u_3
inst✝⁶ : Semifield K
inst✝⁵ : AddCommMonoid V
inst✝⁴ : Module K V
inst✝³ : Projective K V
inst✝² : AddCommMonoid W
inst✝¹ : Module K W
inst✝ : Projective K W
f : End K V ≃ₐ[K] End K W
hV : Nontrivial V
u : V
hu : u ≠ 0
v : Dual K V
huv : v u ≠ 0
z : W
hz : ¬(f (smulRight v u)) z = 0 z
T : V →ₗ[K] W := applyₗ z ∘ₗ f.toLinearMap ∘ₗ smulRightₗ v
hT : ∀ (x : V), T x = (f (smulRight v x)) z
this : ∀ (A : End K V) (x : V), T (A x) = (f A) (T x)
surj : Function.Surjective ⇑T
x y : V
hxy : T x = T y
⊢ (smulRightₗ v) x = (smulRightₗ v) y

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
W : Type u_3
inst✝⁶ : Semifield K
inst✝⁵ : AddCommMonoid V
inst✝⁴ : Module K V
inst✝³ : Projective K V
inst✝² : AddCommMonoid W
inst✝¹ : Module K W
inst✝ : Projective K W
f : End K V ≃ₐ[K] End K W
hV : Nontrivial V
u : V
hu : u ≠ 0
v : Dual K V
huv : v u ≠ 0
z : W
hz : ¬(f (smulRight v u)) z = 0 z
T : V →ₗ[K] W := applyₗ z ∘ₗ f.toLinearMap ∘ₗ smulRightₗ v
hT : ∀ (x : V), T x = (f (smulRight v x)) z
this : ∀ (A : End K V) (x : V), T (A x) = (f A) (T x)
surj : Function.Surjective ⇑T
x y : V
hxy : T x = T y
⊢ x = y

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Ring R
x : R
n : ℕ
hx : (x - x ^ 2) ^ n = 0
⊢ IsIdempotentElem (1 - (1 - x ^ n) ^ n)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e₂ : R
he₂ : IsIdempotentElem e₂
e₁ : R
he₁ : IsIdempotentElem (f e₁)
he₁e₂ : f e₁ * f e₂ = 0
h✝ : Nontrivial R
a : R := e₁ - e₁ * e₂
⊢ f a = f e₁

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
W : Type u_3
inst✝⁶ : Semifield K
inst✝⁵ : AddCommMonoid V
inst✝⁴ : Module K V
inst✝³ : Projective K V
inst✝² : AddCommMonoid W
inst✝¹ : Module K W
inst✝ : Projective K W
f : End K V ≃ₐ[K] End K W
⊢ ∃ T, f = conjAlgEquiv K T

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e₂ : R
he₂ : IsIdempotentElem e₂
e₁ : R
he₁ : IsIdempotentElem (f e₁)
he₁e₂ : f e₁ * f e₂ = 0
h✝ : Nontrivial R
a : R := e₁ - e₁ * e₂
ha : f a = f e₁
⊢ a * e₂ = 0

Tactic:
by

Goal state after:
Module: Mathlib.LinearAlgebra.GeneralLinearGroup.AlgEquiv

Goal state before:
pp: K : Type u_1
V : Type u_2
inst✝³ : Semifield K
inst✝² : AddCommMonoid V
inst✝¹ : Module K V
inst✝ : Projective K V
⊢ Function.Surjective (MulSemiringAction.toAlgEquiv K (End K V))

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e₂ : R
he₂ : IsIdempotentElem e₂
e₁ : R
he₁ : IsIdempotentElem (f e₁)
he₁e₂ : f e₁ * f e₂ = 0
h✝ : Nontrivial R
a : R := e₁ - e₁ * e₂
ha : f a = f e₁
ha' : a * e₂ = 0
⊢ a - a ^ 2 ∈ RingHom.ker f

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e₂ : R
he₂ : IsIdempotentElem e₂
e₁ : R
he₁ : IsIdempotentElem (f e₁)
he₁e₂ : f e₁ * f e₂ = 0
h✝ : Nontrivial R
a : R := e₁ - e₁ * e₂
ha : f a = f e₁
ha' : a * e₂ = 0
hx' : a - a ^ 2 ∈ RingHom.ker f
n : ℕ
hn : (a - a ^ 2) ^ n = 0
k : Rᵐᵒᵖ
hk : MulOpposite.unop (1 ^ n - MulOpposite.op (1 - a ^ n) ^ n) = MulOpposite.unop ((1 - MulOpposite.op (1 - a ^ n)) * k)
⊢ 1 - (1 - a ^ n) ^ n = MulOpposite.unop k * a ^ n

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e₁ : S
he : e₁ ∈ f.range
he₁ : IsIdempotentElem e₁
e₂ : R
he₂ : IsIdempotentElem e₂
he₁e₂ : e₁ * f e₂ = 0
⊢ ∃ e', IsIdempotentElem e' ∧ f e' = e₁ ∧ e' * e₂ = 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e₁ : S
he : e₁ ∈ f.range
he₁ : IsIdempotentElem e₁
e₂ : R
he₂ : IsIdempotentElem e₂
he₁e₂ : e₁ * f e₂ = 0
he₂e₁ : f e₂ * e₁ = 0
⊢ ∃ e', IsIdempotentElem e' ∧ f e' = e₁ ∧ e' * e₂ = 0 ∧ e₂ * e' = 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e : S
he : e ∈ f.range
he' : IsIdempotentElem e
⊢ e * f 0 = 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e : S
he : e ∈ f.range
he' : IsIdempotentElem e
⊢ ∃ e', IsIdempotentElem e' ∧ f e' = e

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
n : ℕ
IH :
  ∀ {e : Fin n → S},
    OrthogonalIdempotents e → (∀ (i : Fin n), e i ∈ f.range) → ∃ e', OrthogonalIdempotents e' ∧ ⇑f ∘ e' = e
e : Fin (n + 1) → S
he : OrthogonalIdempotents e
he' : ∀ (i : Fin (n + 1)), e i ∈ f.range
e' : Fin n → R
h₁ : OrthogonalIdempotents e'
h₂ : ⇑f ∘ e' = e ∘ ⇑(Fin.succEmb n)
h₂' : ∀ (i : Fin n), f (e' i) = e i.succ
⊢ e 0 * f (∑ i ∈ ?m.124, e' i) = 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
n : ℕ
IH :
  ∀ {e : Fin n → S},
    OrthogonalIdempotents e → (∀ (i : Fin n), e i ∈ f.range) → ∃ e', OrthogonalIdempotents e' ∧ ⇑f ∘ e' = e
e : Fin (n + 1) → S
he : OrthogonalIdempotents e
he' : ∀ (i : Fin (n + 1)), e i ∈ f.range
e' : Fin n → R
h₁ : OrthogonalIdempotents e'
h₂ : ⇑f ∘ e' = e ∘ ⇑(Fin.succEmb n)
h₂' : ∀ (i : Fin n), f (e' i) = e i.succ
⊢ f (∑ i ∈ ?m.124, e' i) * e 0 = 0

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝¹ : Ring R
inst✝ : Ring S
f : R →+* S
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
n : ℕ
e : Fin n → S
he : OrthogonalIdempotents e
he' : ∀ (i : Fin n), e i ∈ f.range
⊢ ∃ e', OrthogonalIdempotents e' ∧ ⇑f ∘ e' = e

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : Ring R
inst✝¹ : Ring S
f : R →+* S
I : Type u_3
inst✝ : Finite I
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e : I → S
he : OrthogonalIdempotents e
he' : ∀ (i : I), e i ∈ f.range
val✝ : Fintype I
e' : Fin (Fintype.card I) → R
h₁ : OrthogonalIdempotents e'
h₂ : ⇑f ∘ e' = e ∘ ⇑(Fintype.equivFin I).symm.toEmbedding
⊢ ⇑f ∘ e' ∘ ⇑(Fintype.equivFin I).toEmbedding = e

Tactic:
by

Goal state after:
Module: Mathlib.GroupTheory.Congruence.BigOperators

Goal state before:
pp: ι : Type u_1
M : Type u_2
inst✝ : MulOneClass M
c : Con M
l : List ι
f g : ι → M
h : ∀ x ∈ l, c (f x) (g x)
⊢ c (List.map f l).prod (List.map g l).prod

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : Ring R
inst✝¹ : Ring S
f : R →+* S
I : Type u_3
inst✝ : Finite I
h : ∀ x ∈ RingHom.ker f, IsNilpotent x
e : I → S
he : OrthogonalIdempotents e
he' : ∀ (i : I), e i ∈ f.range
⊢ ∃ e', OrthogonalIdempotents e' ∧ ⇑f ∘ e' = e

Tactic:
by

Goal state after:
Module: Mathlib.GroupTheory.Congruence.BigOperators

Goal state before:
pp: ι : Type u_1
M : Type u_2
inst✝ : MulOneClass M
c : Con M
l : List ι
f : ι → M
⊢ ↑(List.map f l).prod = (List.map (fun i ↦ ↑(f i)) l).prod

Tactic:
by

Goal state after:
Module: Mathlib.GroupTheory.Congruence.BigOperators

Goal state before:
pp: ι : Type u_1
M : Type u_2
inst✝ : CommMonoid M
c : Con M
s : Multiset ι
f g : ι → M
h : ∀ x ∈ s, c (f x) (g x)
⊢ c (Multiset.map f s).prod (Multiset.map g s).prod

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝ : Ring R
x y : R
⊢ CompleteOrthogonalIdempotents ![x, y] ↔ IsIdempotentElem x ∧ y = 1 - x

Tactic:
by

Goal state after:
Module: Mathlib.GroupTheory.Congruence.BigOperators

Goal state before:
pp: ι : Type u_1
M : Type u_2
inst✝ : CommMonoid M
c : Con M
s : Multiset ι
f : ι → M
⊢ ↑(Multiset.map f s).prod = (Multiset.map (fun i ↦ ↑(f i)) s).prod

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Idempotents

Goal state before:
pp: R : Type u_1
inst✝¹ : Ring R
I : Type u_3
e : I → R
inst✝ : Fintype I
he : OrthogonalIdempotents e
⊢ (1 - ∑ i, e i) * ∑ i, e i = 0

Tactic:
by

Goal state after: