clean mathematics

This commit is contained in:
Pietro Monticone 2025-01-14 00:11:17 +01:00
parent fa425ef606
commit d911b3b0f9
5 changed files with 9 additions and 9 deletions

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@ -352,7 +352,7 @@ lemma finExtractTwo_apply_snd {n : } (i : Fin n.succ.succ) (j : Fin n.succ) :
rw [← Equiv.eq_symm_apply]
simp
/-- Takes two maps `Fin n → Fin n` and returns the equivelance they form. -/
/-- Takes two maps `Fin n → Fin n` and returns the equivalence they form. -/
def finMapToEquiv (f1 : Fin n → Fin m) (f2 : Fin m → Fin n)
(h : ∀ x, f1 (f2 x) = x := by decide)
(h' : ∀ x, f2 (f1 x) = x := by decide) : Fin n ≃ Fin m where

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@ -291,11 +291,11 @@ lemma involutionAddEquiv_isSome_image_zero {n : } :
## Equivalences of involutions with no fixed points.
The main aim of thes equivalences is to define `involutionNoFixedZeroEquivProd`.
The main aim of these equivalences is to define `involutionNoFixedZeroEquivProd`.
-/
/-- Fixed point free involutions of `Fin n.succ` can be seperated based on where they sent
/-- Fixed point free involutions of `Fin n.succ` can be separated based on where they sent
`0`. -/
def involutionNoFixedEquivSum {n : } :
{f : Fin n.succ → Fin n.succ // Function.Involutive f
@ -544,7 +544,7 @@ def involutionNoFixedEquivSumSame {n : } :
refine Equiv.trans involutionNoFixedEquivSum ?_
refine Equiv.sigmaCongrRight involutionNoFixedZeroSetEquiv
/-- Ever fixed-point free involutions of `Fin n.succ.succ` can be decomponsed into a
/-- Ever fixed-point free involutions of `Fin n.succ.succ` can be decomposed into a
element of `Fin n.succ` (where `0` is sent) and a fixed-point free involution of
`Fin n`. -/
def involutionNoFixedZeroEquivProd {n : } :

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@ -154,7 +154,7 @@ lemma induction_mod_tmul
# Dependent type version of PiTensorProduct.tmulEquiv
-/
/-- Given two maps `s1` and `s2` whose targets carry an instance of an addative commutative
/-- Given two maps `s1` and `s2` whose targets carry an instance of an additive commutative
monoid, the target of the sum of these two maps also carry an instance thereof. -/
instance : (i : ι1 ⊕ ι2) → AddCommMonoid ((fun i => Sum.elim s1 s2 i) i) := fun i =>
match i with

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@ -57,7 +57,7 @@ lemma subtype_val_eq_toGL : (Subtype.val : SO3 → Matrix (Fin 3) (Fin 3) ) =
Units.val ∘ toGL.toFun :=
rfl
/-- The inclusino of `SO(3)` into `GL(3,)` is an injection. -/
/-- The inclusion of `SO(3)` into `GL(3,)` is an injection. -/
lemma toGL_injective : Function.Injective toGL := by
refine fun A B h ↦ Subtype.eq ?_
rw [@Units.ext_iff] at h

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@ -17,7 +17,7 @@ closed field, e.g., ``, is unitarily similar to an upper triangular matrix.
be decomposed as `A = U * T * star U` where `U` is unitary and `T` is upper triangular.
- `Matrix.schurTriangulationUnitary` : the unitary matrix `U` as previously stated.
- `Matrix.schurTriangulation` : the upper triangular matrix `T` as previously stated.
- Some auxilary definitions are not meant to be used directly, but
- Some auxiliary definitions are not meant to be used directly, but
`LinearMap.SchurTriangulationAux.of` contains the main algorithm for the triangulation procedure.
-/
@ -124,8 +124,8 @@ end
Given a linear endomorphism `f` on a non-trivial finite-dimensional vector space `E` over an
algebraically closed field `𝕜`, one can always pick an eigenvalue `μ` of `f` whose corresponding
eigenspace `V` is non-trivial. Given that `E` is also an inner product space, let `bV` and `bW` be
othonormal bases for `V` and `Vᗮ` respectively. Then, the collection of vectors in `bV` and `bW`
forms an othornomal basis `bE` for `E`, as the direct sum of `V` and `Vᗮ` is an internal
orthonormal bases for `V` and `Vᗮ` respectively. Then, the collection of vectors in `bV` and `bW`
forms an orthonormal basis `bE` for `E`, as the direct sum of `V` and `Vᗮ` is an internal
decomposition of `E`. The matrix representation of `f` with respect to `bE` satisfies
$$
\sideset{_\mathrm{bE}}{_\mathrm{bE}}{[f]} =