Interactions between embeddings and sets. #
@[simp]
theorem
Function.Embedding.coeWithTop_apply
{α : Type u_1}
:
∀ (a : α), Function.Embedding.coeWithTop a = ↑a
@[simp]
theorem
Function.Embedding.optionElim_apply
{α : Type u_1}
{β : Type u_2}
(f : α ↪ β)
(x : β)
(h : x ∉ Set.range ⇑f)
:
∀ (a : Option α), (Function.Embedding.optionElim f x h) a = Option.elim' x (⇑f) a
def
Function.Embedding.optionElim
{α : Type u_1}
{β : Type u_2}
(f : α ↪ β)
(x : β)
(h : x ∉ Set.range ⇑f)
:
Given an embedding f : α ↪ β
and a point outside of Set.range f
, construct an embedding
Option α ↪ β
.
Equations
- Function.Embedding.optionElim f x h = { toFun := Option.elim' x ⇑f, inj' := ⋯ }
Instances For
@[simp]
theorem
Function.Embedding.optionEmbeddingEquiv_apply_fst
(α : Type u_1)
(β : Type u_2)
(f : Option α ↪ β)
:
((Function.Embedding.optionEmbeddingEquiv α β) f).fst = Function.Embedding.trans Function.Embedding.coeWithTop f
@[simp]
theorem
Function.Embedding.optionEmbeddingEquiv_symm_apply
(α : Type u_1)
(β : Type u_2)
(f : (f : α ↪ β) × ↑(Set.range ⇑f)ᶜ)
:
(Function.Embedding.optionEmbeddingEquiv α β).symm f = Function.Embedding.optionElim f.fst ↑f.snd ⋯
@[simp]
theorem
Function.Embedding.optionEmbeddingEquiv_apply_snd_coe
(α : Type u_1)
(β : Type u_2)
(f : Option α ↪ β)
:
↑((Function.Embedding.optionEmbeddingEquiv α β) f).snd = f none
def
Function.Embedding.codRestrict
{α : Sort u_1}
{β : Type u_2}
(p : Set β)
(f : α ↪ β)
(H : ∀ (a : α), f a ∈ p)
:
α ↪ ↑p
Restrict the codomain of an embedding.
Equations
- Function.Embedding.codRestrict p f H = { toFun := fun (a : α) => { val := f a, property := ⋯ }, inj' := ⋯ }
Instances For
@[simp]
theorem
Function.Embedding.codRestrict_apply
{α : Sort u_1}
{β : Type u_2}
(p : Set β)
(f : α ↪ β)
(H : ∀ (a : α), f a ∈ p)
(a : α)
:
(Function.Embedding.codRestrict p f H) a = { val := f a, property := ⋯ }
@[simp]
theorem
Function.Embedding.image_apply
{α : Type u_1}
{β : Type u_2}
(f : α ↪ β)
(s : Set α)
:
(Function.Embedding.image f) s = ⇑f '' s
@[simp]
theorem
Set.embeddingOfSubset_apply_coe
{α : Type u_1}
(s : Set α)
(t : Set α)
(h : s ⊆ t)
(x : ↑s)
:
↑((Set.embeddingOfSubset s t h) x) = ↑x
The injection map is an embedding between subsets.
Equations
- Set.embeddingOfSubset s t h = { toFun := fun (x : ↑s) => { val := ↑x, property := ⋯ }, inj' := ⋯ }
Instances For
@[simp]
theorem
subtypeOrEquiv_apply
{α : Type u_1}
(p : α → Prop)
(q : α → Prop)
[DecidablePred p]
(h : Disjoint p q)
(a : { x : α // p x ∨ q x })
:
(subtypeOrEquiv p q h) a = (subtypeOrLeftEmbedding p q) a
def
subtypeOrEquiv
{α : Type u_1}
(p : α → Prop)
(q : α → Prop)
[DecidablePred p]
(h : Disjoint p q)
:
A subtype {x // p x ∨ q x}
over a disjunction of p q : α → Prop
is equivalent to a sum of
subtypes {x // p x} ⊕ {x // q x}
such that ¬ p x
is sent to the right, when
Disjoint p q
.
See also Equiv.sumCompl
, for when IsCompl p q
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
@[simp]
theorem
subtypeOrEquiv_symm_inl
{α : Type u_1}
(p : α → Prop)
(q : α → Prop)
[DecidablePred p]
(h : Disjoint p q)
(x : { x : α // p x })
:
(subtypeOrEquiv p q h).symm (Sum.inl x) = { val := ↑x, property := ⋯ }
@[simp]
theorem
subtypeOrEquiv_symm_inr
{α : Type u_1}
(p : α → Prop)
(q : α → Prop)
[DecidablePred p]
(h : Disjoint p q)
(x : { x : α // q x })
:
(subtypeOrEquiv p q h).symm (Sum.inr x) = { val := ↑x, property := ⋯ }