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case zero α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β g : β → γ f : α → α ⊢ preimage f^[Nat.zero] = (preimage f)^[Nat.zero]
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
theorem preimage_iterate_eq {f : α → α} {n : ℕ} : Set.preimage f^[n] = (Set.preimage f)^[n] := by induction' n with n ih; ·
Mathlib.Data.Set.Image.171_0.IJFiTzmYGOCpPSd
theorem preimage_iterate_eq {f : α → α} {n : ℕ} : Set.preimage f^[n] = (Set.preimage f)^[n]
Mathlib_Data_Set_Image
case succ α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β g : β → γ f : α → α n : ℕ ih : preimage f^[n] = (preimage f)^[n] ⊢ preimage f^[Nat.succ n] = (preimage f)^[Nat.succ n]
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [iterate_succ, iterate_succ', preimage_comp_eq, ih]
theorem preimage_iterate_eq {f : α → α} {n : ℕ} : Set.preimage f^[n] = (Set.preimage f)^[n] := by induction' n with n ih; · simp
Mathlib.Data.Set.Image.171_0.IJFiTzmYGOCpPSd
theorem preimage_iterate_eq {f : α → α} {n : ℕ} : Set.preimage f^[n] = (Set.preimage f)^[n]
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ p : α → Prop s : Set (Subtype p) t : Set α s_eq : s = Subtype.val ⁻¹' t x : α h : p x ⊢ { val := x, property := h } ∈ s ↔ x ∈ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [s_eq]
theorem eq_preimage_subtype_val_iff {p : α → Prop} {s : Set (Subtype p)} {t : Set α} : s = Subtype.val ⁻¹' t ↔ ∀ (x) (h : p x), (⟨x, h⟩ : Subtype p) ∈ s ↔ x ∈ t := ⟨fun s_eq x h => by
Mathlib.Data.Set.Image.181_0.IJFiTzmYGOCpPSd
theorem eq_preimage_subtype_val_iff {p : α → Prop} {s : Set (Subtype p)} {t : Set α} : s = Subtype.val ⁻¹' t ↔ ∀ (x) (h : p x), (⟨x, h⟩ : Subtype p) ∈ s ↔ x ∈ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ p : α → Prop s : Set (Subtype p) t : Set α s_eq : s = Subtype.val ⁻¹' t x : α h : p x ⊢ { val := x, property := h } ∈ Subtype.val ⁻¹' t ↔ x ∈ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
theorem eq_preimage_subtype_val_iff {p : α → Prop} {s : Set (Subtype p)} {t : Set α} : s = Subtype.val ⁻¹' t ↔ ∀ (x) (h : p x), (⟨x, h⟩ : Subtype p) ∈ s ↔ x ∈ t := ⟨fun s_eq x h => by rw [s_eq]
Mathlib.Data.Set.Image.181_0.IJFiTzmYGOCpPSd
theorem eq_preimage_subtype_val_iff {p : α → Prop} {s : Set (Subtype p)} {t : Set α} : s = Subtype.val ⁻¹' t ↔ ∀ (x) (h : p x), (⟨x, h⟩ : Subtype p) ∈ s ↔ x ∈ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ p : α → Prop s : Set (Subtype p) t : Set α h : ∀ (x : α) (h : p x), { val := x, property := h } ∈ s ↔ x ∈ t x✝ : Subtype p x : α hx : p x ⊢ { val := x, property := hx } ∈ s ↔ { val := x, property := hx } ∈ Subtype.val ⁻¹' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp [h]
theorem eq_preimage_subtype_val_iff {p : α → Prop} {s : Set (Subtype p)} {t : Set α} : s = Subtype.val ⁻¹' t ↔ ∀ (x) (h : p x), (⟨x, h⟩ : Subtype p) ∈ s ↔ x ∈ t := ⟨fun s_eq x h => by rw [s_eq] simp, fun h => ext fun ⟨x, hx⟩ => by
Mathlib.Data.Set.Image.181_0.IJFiTzmYGOCpPSd
theorem eq_preimage_subtype_val_iff {p : α → Prop} {s : Set (Subtype p)} {t : Set α} : s = Subtype.val ⁻¹' t ↔ ∀ (x) (h : p x), (⟨x, h⟩ : Subtype p) ∈ s ↔ x ∈ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ p : α → Prop ⊢ p ⁻¹' {True} = {a | p a}
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
@[simp] theorem preimage_singleton_true (p : α → Prop) : p ⁻¹' {True} = {a | p a} := by
Mathlib.Data.Set.Image.194_0.IJFiTzmYGOCpPSd
@[simp] theorem preimage_singleton_true (p : α → Prop) : p ⁻¹' {True} = {a | p a}
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ p : α → Prop x✝ : α ⊢ x✝ ∈ p ⁻¹' {True} ↔ x✝ ∈ {a | p a}
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
@[simp] theorem preimage_singleton_true (p : α → Prop) : p ⁻¹' {True} = {a | p a} := by ext;
Mathlib.Data.Set.Image.194_0.IJFiTzmYGOCpPSd
@[simp] theorem preimage_singleton_true (p : α → Prop) : p ⁻¹' {True} = {a | p a}
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ p : α → Prop ⊢ p ⁻¹' {False} = {a | ¬p a}
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
@[simp] theorem preimage_singleton_false (p : α → Prop) : p ⁻¹' {False} = {a | ¬p a} := by
Mathlib.Data.Set.Image.197_0.IJFiTzmYGOCpPSd
@[simp] theorem preimage_singleton_false (p : α → Prop) : p ⁻¹' {False} = {a | ¬p a}
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ p : α → Prop x✝ : α ⊢ x✝ ∈ p ⁻¹' {False} ↔ x✝ ∈ {a | ¬p a}
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
@[simp] theorem preimage_singleton_false (p : α → Prop) : p ⁻¹' {False} = {a | ¬p a} := by ext;
Mathlib.Data.Set.Image.197_0.IJFiTzmYGOCpPSd
@[simp] theorem preimage_singleton_false (p : α → Prop) : p ⁻¹' {False} = {a | ¬p a}
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ s u v : Set α hsuv : s ⊆ u ∪ v H : s ∩ (u ∩ v) = ∅ ⊢ Subtype.val ⁻¹' u = (Subtype.val ⁻¹' v)ᶜ
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext ⟨x, x_in_s⟩
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ := by
Mathlib.Data.Set.Image.200_0.IJFiTzmYGOCpPSd
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ
Mathlib_Data_Set_Image
case h.mk α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ s u v : Set α hsuv : s ⊆ u ∪ v H : s ∩ (u ∩ v) = ∅ x : α x_in_s : x ∈ s ⊢ { val := x, property := x_in_s } ∈ Subtype.val ⁻¹' u ↔ { val := x, property := x_in_s } ∈ (Subtype.val ⁻¹' v)ᶜ
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
constructor
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ := by ext ⟨x, x_in_s⟩
Mathlib.Data.Set.Image.200_0.IJFiTzmYGOCpPSd
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ
Mathlib_Data_Set_Image
case h.mk.mp α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ s u v : Set α hsuv : s ⊆ u ∪ v H : s ∩ (u ∩ v) = ∅ x : α x_in_s : x ∈ s ⊢ { val := x, property := x_in_s } ∈ Subtype.val ⁻¹' u → { val := x, property := x_in_s } ∈ (Subtype.val ⁻¹' v)ᶜ
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
intro x_in_u x_in_v
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ := by ext ⟨x, x_in_s⟩ constructor ·
Mathlib.Data.Set.Image.200_0.IJFiTzmYGOCpPSd
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ
Mathlib_Data_Set_Image
case h.mk.mp α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ s u v : Set α hsuv : s ⊆ u ∪ v H : s ∩ (u ∩ v) = ∅ x : α x_in_s : x ∈ s x_in_u : { val := x, property := x_in_s } ∈ Subtype.val ⁻¹' u x_in_v : { val := x, property := x_in_s } ∈ Subtype.val ⁻¹' v ⊢ False
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact eq_empty_iff_forall_not_mem.mp H x ⟨x_in_s, ⟨x_in_u, x_in_v⟩⟩
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ := by ext ⟨x, x_in_s⟩ constructor · intro x_in_u x_in_v
Mathlib.Data.Set.Image.200_0.IJFiTzmYGOCpPSd
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ
Mathlib_Data_Set_Image
case h.mk.mpr α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ s u v : Set α hsuv : s ⊆ u ∪ v H : s ∩ (u ∩ v) = ∅ x : α x_in_s : x ∈ s ⊢ { val := x, property := x_in_s } ∈ (Subtype.val ⁻¹' v)ᶜ → { val := x, property := x_in_s } ∈ Subtype.val ⁻¹' u
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
intro hx
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ := by ext ⟨x, x_in_s⟩ constructor · intro x_in_u x_in_v exact eq_empty_iff_forall_not_mem.mp H x ⟨x_in_s, ⟨x_in_u, x_in_v⟩⟩ ·
Mathlib.Data.Set.Image.200_0.IJFiTzmYGOCpPSd
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ
Mathlib_Data_Set_Image
case h.mk.mpr α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β g : β → γ s u v : Set α hsuv : s ⊆ u ∪ v H : s ∩ (u ∩ v) = ∅ x : α x_in_s : x ∈ s hx : { val := x, property := x_in_s } ∈ (Subtype.val ⁻¹' v)ᶜ ⊢ { val := x, property := x_in_s } ∈ Subtype.val ⁻¹' u
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact Or.elim (hsuv x_in_s) id fun hx' => hx.elim hx'
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ := by ext ⟨x, x_in_s⟩ constructor · intro x_in_u x_in_v exact eq_empty_iff_forall_not_mem.mp H x ⟨x_in_s, ⟨x_in_u, x_in_v⟩⟩ · intro hx
Mathlib.Data.Set.Image.200_0.IJFiTzmYGOCpPSd
theorem preimage_subtype_coe_eq_compl {s u v : Set α} (hsuv : s ⊆ u ∪ v) (H : s ∩ (u ∩ v) = ∅) : ((↑) : s → α) ⁻¹' u = ((↑) ⁻¹' v)ᶜ
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β s : Set α p : β → Prop ⊢ (∀ y ∈ f '' s, p y) ↔ ∀ x ∈ s, p (f x)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
theorem ball_image_iff {f : α → β} {s : Set α} {p : β → Prop} : (∀ y ∈ f '' s, p y) ↔ ∀ x ∈ s, p (f x) := by
Mathlib.Data.Set.Image.249_0.IJFiTzmYGOCpPSd
theorem ball_image_iff {f : α → β} {s : Set α} {p : β → Prop} : (∀ y ∈ f '' s, p y) ↔ ∀ x ∈ s, p (f x)
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β s : Set α p : β → Prop ⊢ (∃ y ∈ f '' s, p y) ↔ ∃ x ∈ s, p (f x)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
theorem bex_image_iff {f : α → β} {s : Set α} {p : β → Prop} : (∃ y ∈ f '' s, p y) ↔ ∃ x ∈ s, p (f x) := by
Mathlib.Data.Set.Image.258_0.IJFiTzmYGOCpPSd
theorem bex_image_iff {f : α → β} {s : Set α} {p : β → Prop} : (∃ y ∈ f '' s, p y) ↔ ∃ x ∈ s, p (f x)
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f g : α → β s : Set α h : ∀ a ∈ s, f a = g a ⊢ f '' s = g '' s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext x
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by
Mathlib.Data.Set.Image.273_0.IJFiTzmYGOCpPSd
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f g : α → β s : Set α h : ∀ a ∈ s, f a = g a x : β ⊢ x ∈ f '' s ↔ x ∈ g '' s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [mem_image, mem_image]
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by ext x
Mathlib.Data.Set.Image.273_0.IJFiTzmYGOCpPSd
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f g : α → β s : Set α h : ∀ a ∈ s, f a = g a x : β ⊢ (∃ x_1 ∈ s, f x_1 = x) ↔ ∃ x_1 ∈ s, g x_1 = x
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact { mp := by rintro ⟨a, ha1, ha2⟩ exact ⟨a, ⟨ha1, (h a ha1) ▸ ha2⟩⟩, mpr := by rintro ⟨a, ha1, ha2⟩ exact ⟨a, ⟨ha1, (h a ha1) ▸ ha2⟩⟩ }
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by ext x rw [mem_image, mem_image]
Mathlib.Data.Set.Image.273_0.IJFiTzmYGOCpPSd
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f g : α → β s : Set α h : ∀ a ∈ s, f a = g a x : β ⊢ (∃ x_1 ∈ s, f x_1 = x) → ∃ x_1 ∈ s, g x_1 = x
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro ⟨a, ha1, ha2⟩
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by ext x rw [mem_image, mem_image] exact { mp := by
Mathlib.Data.Set.Image.273_0.IJFiTzmYGOCpPSd
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s
Mathlib_Data_Set_Image
case intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f g : α → β s : Set α h : ∀ a ∈ s, f a = g a x : β a : α ha1 : a ∈ s ha2 : f a = x ⊢ ∃ x_1 ∈ s, g x_1 = x
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact ⟨a, ⟨ha1, (h a ha1) ▸ ha2⟩⟩
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by ext x rw [mem_image, mem_image] exact { mp := by rintro ⟨a, ha1, ha2⟩
Mathlib.Data.Set.Image.273_0.IJFiTzmYGOCpPSd
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f g : α → β s : Set α h : ∀ a ∈ s, f a = g a x : β ⊢ (∃ x_1 ∈ s, g x_1 = x) → ∃ x_1 ∈ s, f x_1 = x
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro ⟨a, ha1, ha2⟩
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by ext x rw [mem_image, mem_image] exact { mp := by rintro ⟨a, ha1, ha2⟩ exact ⟨a, ⟨ha1, (h a ha1) ▸ ha2⟩⟩, mpr := by
Mathlib.Data.Set.Image.273_0.IJFiTzmYGOCpPSd
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s
Mathlib_Data_Set_Image
case intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f g : α → β s : Set α h : ∀ a ∈ s, f a = g a x : β a : α ha1 : a ∈ s ha2 : g a = x ⊢ ∃ x_1 ∈ s, f x_1 = x
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact ⟨a, ⟨ha1, (h a ha1) ▸ ha2⟩⟩
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by ext x rw [mem_image, mem_image] exact { mp := by rintro ⟨a, ha1, ha2⟩ exact ⟨a, ⟨ha1, (h a ha1) ▸ ha2⟩⟩, mpr := by rintro ⟨a, ha1, ha2⟩
Mathlib.Data.Set.Image.273_0.IJFiTzmYGOCpPSd
@[congr] theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t : Set α h : s ⊆ t ⊢ f '' s ⊆ f '' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro - ⟨a, ha, rfl⟩
@[gcongr] lemma image_mono (h : s ⊆ t) : f '' s ⊆ f '' t := by
Mathlib.Data.Set.Image.293_0.IJFiTzmYGOCpPSd
@[gcongr] lemma image_mono (h : s ⊆ t) : f '' s ⊆ f '' t
Mathlib_Data_Set_Image
case intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t : Set α h : s ⊆ t a : α ha : a ∈ s ⊢ f a ∈ f '' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact mem_image_of_mem f (h ha)
@[gcongr] lemma image_mono (h : s ⊆ t) : f '' s ⊆ f '' t := by rintro - ⟨a, ha, rfl⟩;
Mathlib.Data.Set.Image.293_0.IJFiTzmYGOCpPSd
@[gcongr] lemma image_mono (h : s ⊆ t) : f '' s ⊆ f '' t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t : Set α g : β → γ ⊢ image (g ∘ f) = image g ∘ image f
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
theorem image_comp_eq {g : β → γ} : image (g ∘ f) = image g ∘ image f := by
Mathlib.Data.Set.Image.302_0.IJFiTzmYGOCpPSd
theorem image_comp_eq {g : β → γ} : image (g ∘ f) = image g ∘ image f
Mathlib_Data_Set_Image
case h.h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t : Set α g : β → γ x✝¹ : Set α x✝ : γ ⊢ x✝ ∈ g ∘ f '' x✝¹ ↔ x✝ ∈ (image g ∘ image f) x✝¹
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
theorem image_comp_eq {g : β → γ} : image (g ∘ f) = image g ∘ image f := by ext;
Mathlib.Data.Set.Image.302_0.IJFiTzmYGOCpPSd
theorem image_comp_eq {g : β → γ} : image (g ∘ f) = image g ∘ image f
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α β' : Type u_6 f : β → γ g : α → β f' : α → β' g' : β' → γ h_comm : ∀ (a : α), f (g a) = g' (f' a) ⊢ f '' (g '' s) = g' '' (f' '' s)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp_rw [image_image, h_comm]
theorem image_comm {β'} {f : β → γ} {g : α → β} {f' : α → β'} {g' : β' → γ} (h_comm : ∀ a, f (g a) = g' (f' a)) : (s.image g).image f = (s.image f').image g' := by
Mathlib.Data.Set.Image.309_0.IJFiTzmYGOCpPSd
theorem image_comm {β'} {f : β → γ} {g : α → β} {f' : α → β'} {g' : β' → γ} (h_comm : ∀ a, f (g a) = g' (f' a)) : (s.image g).image f = (s.image f').image g'
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t a b : Set α f : α → β h : a ⊆ b ⊢ f '' a ⊆ f '' b
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp only [subset_def, mem_image]
/-- Image is monotone with respect to `⊆`. See `Set.monotone_image` for the statement in terms of `≤`. -/ @[gcongr] theorem image_subset {a b : Set α} (f : α → β) (h : a ⊆ b) : f '' a ⊆ f '' b := by
Mathlib.Data.Set.Image.324_0.IJFiTzmYGOCpPSd
/-- Image is monotone with respect to `⊆`. See `Set.monotone_image` for the statement in terms of `≤`. -/ @[gcongr] theorem image_subset {a b : Set α} (f : α → β) (h : a ⊆ b) : f '' a ⊆ f '' b
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t a b : Set α f : α → β h : a ⊆ b ⊢ ∀ (x : β), (∃ x_1 ∈ a, f x_1 = x) → ∃ x_1 ∈ b, f x_1 = x
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact fun x => fun ⟨w, h1, h2⟩ => ⟨w, h h1, h2⟩
/-- Image is monotone with respect to `⊆`. See `Set.monotone_image` for the statement in terms of `≤`. -/ @[gcongr] theorem image_subset {a b : Set α} (f : α → β) (h : a ⊆ b) : f '' a ⊆ f '' b := by simp only [subset_def, mem_image]
Mathlib.Data.Set.Image.324_0.IJFiTzmYGOCpPSd
/-- Image is monotone with respect to `⊆`. See `Set.monotone_image` for the statement in terms of `≤`. -/ @[gcongr] theorem image_subset {a b : Set α} (f : α → β) (h : a ⊆ b) : f '' a ⊆ f '' b
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α x : β ⊢ x ∈ f '' (s ∪ t) → x ∈ f '' s ∪ f '' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro ⟨a, h | h, rfl⟩ <;> [left; right]
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α x : β ⊢ x ∈ f '' (s ∪ t) → x ∈ f '' s ∪ f '' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro ⟨a, h | h, rfl⟩
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case intro.intro.inl α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ s ⊢ f a ∈ f '' s ∪ f '' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
left
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case intro.intro.inr α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ t ⊢ f a ∈ f '' s ∪ f '' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
right
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left;
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case intro.intro.inl.h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ s ⊢ f a ∈ f '' s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact ⟨_, h, rfl⟩
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;>
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case intro.intro.inr.h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ t ⊢ f a ∈ f '' t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact ⟨_, h, rfl⟩
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;>
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α x : β ⊢ x ∈ f '' s ∪ f '' t → x ∈ f '' (s ∪ t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;> refine' ⟨_, _, rfl⟩ <;> [left; right]
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α x : β ⊢ x ∈ f '' s ∪ f '' t → x ∈ f '' (s ∪ t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩)
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case inl.intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ s ⊢ f a ∈ f '' (s ∪ t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
refine' ⟨_, _, rfl⟩
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;>
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case inr.intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ t ⊢ f a ∈ f '' (s ∪ t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
refine' ⟨_, _, rfl⟩
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;>
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case inl.intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ s ⊢ a ∈ s ∪ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
left
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;> refine' ⟨_, _, rfl⟩ <;> [
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case inr.intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ t ⊢ a ∈ s ∪ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
right
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;> refine' ⟨_, _, rfl⟩ <;> [left;
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case inl.intro.intro.h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ s ⊢ a ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact h
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;> refine' ⟨_, _, rfl⟩ <;> [left; right] <;>
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
case inr.intro.intro.h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α a : α h : a ∈ t ⊢ a ∈ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact h
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t := ext fun x => ⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;> refine' ⟨_, _, rfl⟩ <;> [left; right] <;>
Mathlib.Data.Set.Image.336_0.IJFiTzmYGOCpPSd
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β ⊢ f '' ∅ = ∅
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
@[simp] theorem image_empty (f : α → β) : f '' ∅ = ∅ := by
Mathlib.Data.Set.Image.342_0.IJFiTzmYGOCpPSd
@[simp] theorem image_empty (f : α → β) : f '' ∅ = ∅
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β x✝ : β ⊢ x✝ ∈ f '' ∅ ↔ x✝ ∈ ∅
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
@[simp] theorem image_empty (f : α → β) : f '' ∅ = ∅ := by ext
Mathlib.Data.Set.Image.342_0.IJFiTzmYGOCpPSd
@[simp] theorem image_empty (f : α → β) : f '' ∅ = ∅
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α h : ∀ x ∈ t, ∀ y ∈ s, f x = f y → x = y b : β x✝ : b ∈ f '' s ∩ f '' t a₁ : α ha₁ : a₁ ∈ s h₁ : f a₁ = b a₂ : α ha₂ : a₂ ∈ t h₂ : f a₂ = b ⊢ f a₂ = f a₁
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp [*]
theorem image_inter_on {f : α → β} {s t : Set α} (h : ∀ x ∈ t, ∀ y ∈ s, f x = f y → x = y) : f '' (s ∩ t) = f '' s ∩ f '' t := (image_inter_subset _ _ _).antisymm fun b ⟨⟨a₁, ha₁, h₁⟩, ⟨a₂, ha₂, h₂⟩⟩ ↦ have : a₂ = a₁ := h _ ha₂ _ ha₁ (by
Mathlib.Data.Set.Image.352_0.IJFiTzmYGOCpPSd
theorem image_inter_on {f : α → β} {s t : Set α} (h : ∀ x ∈ t, ∀ y ∈ s, f x = f y → x = y) : f '' (s ∩ t) = f '' s ∩ f '' t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι✝ : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α ι : Type u_6 f : ι → β H : Surjective f ⊢ ∀ (x : β), x ∈ f '' univ
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simpa [image]
theorem image_univ_of_surjective {ι : Type*} {f : ι → β} (H : Surjective f) : f '' univ = univ := eq_univ_of_forall <| by
Mathlib.Data.Set.Image.364_0.IJFiTzmYGOCpPSd
theorem image_univ_of_surjective {ι : Type*} {f : ι → β} (H : Surjective f) : f '' univ = univ
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β a : α ⊢ f '' {a} = {f a}
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
@[simp] theorem image_singleton {f : α → β} {a : α} : f '' {a} = {f a} := by
Mathlib.Data.Set.Image.368_0.IJFiTzmYGOCpPSd
@[simp] theorem image_singleton {f : α → β} {a : α} : f '' {a} = {f a}
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β a : α x✝ : β ⊢ x✝ ∈ f '' {a} ↔ x✝ ∈ {f a}
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp [image, eq_comm]
@[simp] theorem image_singleton {f : α → β} {a : α} : f '' {a} = {f a} := by ext
Mathlib.Data.Set.Image.368_0.IJFiTzmYGOCpPSd
@[simp] theorem image_singleton {f : α → β} {a : α} : f '' {a} = {f a}
Mathlib_Data_Set_Image
α✝ : Type u_1 β✝ : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α✝ → β✝ s✝ t : Set α✝ α : Type u_6 β : Type u_7 f : α → β s : Set α ⊢ f '' s = ∅ ↔ s = ∅
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp only [eq_empty_iff_forall_not_mem]
@[simp, mfld_simps] theorem image_eq_empty {α β} {f : α → β} {s : Set α} : f '' s = ∅ ↔ s = ∅ := by
Mathlib.Data.Set.Image.381_0.IJFiTzmYGOCpPSd
@[simp, mfld_simps] theorem image_eq_empty {α β} {f : α → β} {s : Set α} : f '' s = ∅ ↔ s = ∅
Mathlib_Data_Set_Image
α✝ : Type u_1 β✝ : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α✝ → β✝ s✝ t : Set α✝ α : Type u_6 β : Type u_7 f : α → β s : Set α ⊢ (∀ (x : β), x ∉ f '' s) ↔ ∀ (x : α), x ∉ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact ⟨fun H a ha => H _ ⟨_, ha, rfl⟩, fun H b ⟨_, ha, _⟩ => H _ ha⟩
@[simp, mfld_simps] theorem image_eq_empty {α β} {f : α → β} {s : Set α} : f '' s = ∅ ↔ s = ∅ := by simp only [eq_empty_iff_forall_not_mem]
Mathlib.Data.Set.Image.381_0.IJFiTzmYGOCpPSd
@[simp, mfld_simps] theorem image_eq_empty {α β} {f : α → β} {s : Set α} : f '' s = ∅ ↔ s = ∅
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t✝ : Set α inst✝ : BooleanAlgebra α t : α S : Set α ⊢ t ∈ compl '' S ↔ tᶜ ∈ S
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp [← preimage_compl_eq_image_compl]
theorem mem_compl_image [BooleanAlgebra α] (t : α) (S : Set α) : t ∈ HasCompl.compl '' S ↔ tᶜ ∈ S := by
Mathlib.Data.Set.Image.395_0.IJFiTzmYGOCpPSd
theorem mem_compl_image [BooleanAlgebra α] (t : α) (S : Set α) : t ∈ HasCompl.compl '' S ↔ tᶜ ∈ S
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t : Set α ⊢ image id = id
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
@[simp] theorem image_id_eq : image (id : α → α) = id := by
Mathlib.Data.Set.Image.400_0.IJFiTzmYGOCpPSd
@[simp] theorem image_id_eq : image (id : α → α) = id
Mathlib_Data_Set_Image
case h.h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t x✝¹ : Set α x✝ : α ⊢ x✝ ∈ id '' x✝¹ ↔ x✝ ∈ id x✝¹
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
@[simp] theorem image_id_eq : image (id : α → α) = id := by ext;
Mathlib.Data.Set.Image.400_0.IJFiTzmYGOCpPSd
@[simp] theorem image_id_eq : image (id : α → α) = id
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α ⊢ (fun x => x) '' s = s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
/-- A variant of `image_id` -/ @[simp] theorem image_id' (s : Set α) : (fun x => x) '' s = s := by
Mathlib.Data.Set.Image.403_0.IJFiTzmYGOCpPSd
/-- A variant of `image_id` -/ @[simp] theorem image_id' (s : Set α) : (fun x => x) '' s = s
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α x✝ : α ⊢ x✝ ∈ (fun x => x) '' s ↔ x✝ ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
/-- A variant of `image_id` -/ @[simp] theorem image_id' (s : Set α) : (fun x => x) '' s = s := by ext
Mathlib.Data.Set.Image.403_0.IJFiTzmYGOCpPSd
/-- A variant of `image_id` -/ @[simp] theorem image_id' (s : Set α) : (fun x => x) '' s = s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α ⊢ id '' s = s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
theorem image_id (s : Set α) : id '' s = s := by
Mathlib.Data.Set.Image.410_0.IJFiTzmYGOCpPSd
theorem image_id (s : Set α) : id '' s = s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → α n : ℕ ⊢ image f^[n] = (image f)^[n]
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
induction' n with n ih
lemma image_iterate_eq {f : α → α} {n : ℕ} : image (f^[n]) = (image f)^[n] := by
Mathlib.Data.Set.Image.413_0.IJFiTzmYGOCpPSd
lemma image_iterate_eq {f : α → α} {n : ℕ} : image (f^[n]) = (image f)^[n]
Mathlib_Data_Set_Image
case zero α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → α ⊢ image f^[Nat.zero] = (image f)^[Nat.zero]
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp
lemma image_iterate_eq {f : α → α} {n : ℕ} : image (f^[n]) = (image f)^[n] := by induction' n with n ih; ·
Mathlib.Data.Set.Image.413_0.IJFiTzmYGOCpPSd
lemma image_iterate_eq {f : α → α} {n : ℕ} : image (f^[n]) = (image f)^[n]
Mathlib_Data_Set_Image
case succ α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → α n : ℕ ih : image f^[n] = (image f)^[n] ⊢ image f^[Nat.succ n] = (image f)^[Nat.succ n]
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [iterate_succ', iterate_succ',← ih, image_comp_eq]
lemma image_iterate_eq {f : α → α} {n : ℕ} : image (f^[n]) = (image f)^[n] := by induction' n with n ih; · simp
Mathlib.Data.Set.Image.413_0.IJFiTzmYGOCpPSd
lemma image_iterate_eq {f : α → α} {n : ℕ} : image (f^[n]) = (image f)^[n]
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s t : Set α inst✝ : BooleanAlgebra α S : Set α ⊢ compl '' (compl '' S) = S
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [← image_comp, compl_comp_compl, image_id]
theorem compl_compl_image [BooleanAlgebra α] (S : Set α) : HasCompl.compl '' (HasCompl.compl '' S) = S := by
Mathlib.Data.Set.Image.417_0.IJFiTzmYGOCpPSd
theorem compl_compl_image [BooleanAlgebra α] (S : Set α) : HasCompl.compl '' (HasCompl.compl '' S) = S
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β a : α s : Set α ⊢ f '' insert a s = insert (f a) (f '' s)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext
theorem image_insert_eq {f : α → β} {a : α} {s : Set α} : f '' insert a s = insert (f a) (f '' s) := by
Mathlib.Data.Set.Image.422_0.IJFiTzmYGOCpPSd
theorem image_insert_eq {f : α → β} {a : α} {s : Set α} : f '' insert a s = insert (f a) (f '' s)
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β a : α s : Set α x✝ : β ⊢ x✝ ∈ f '' insert a s ↔ x✝ ∈ insert (f a) (f '' s)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp [and_or_left, exists_or, eq_comm, or_comm, and_comm]
theorem image_insert_eq {f : α → β} {a : α} {s : Set α} : f '' insert a s = insert (f a) (f '' s) := by ext
Mathlib.Data.Set.Image.422_0.IJFiTzmYGOCpPSd
theorem image_insert_eq {f : α → β} {a : α} {s : Set α} : f '' insert a s = insert (f a) (f '' s)
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β a b : α ⊢ f '' {a, b} = {f a, f b}
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp only [image_insert_eq, image_singleton]
theorem image_pair (f : α → β) (a b : α) : f '' {a, b} = {f a, f b} := by
Mathlib.Data.Set.Image.428_0.IJFiTzmYGOCpPSd
theorem image_pair (f : α → β) (a b : α) : f '' {a, b} = {f a, f b}
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β g : β → α b : β s : Set α h₁ : LeftInverse g f h₂ : Function.RightInverse g f ⊢ b ∈ f '' s ↔ g b ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [image_eq_preimage_of_inverse h₁ h₂]
theorem mem_image_iff_of_inverse {f : α → β} {g : β → α} {b : β} {s : Set α} (h₁ : LeftInverse g f) (h₂ : RightInverse g f) : b ∈ f '' s ↔ g b ∈ s := by
Mathlib.Data.Set.Image.446_0.IJFiTzmYGOCpPSd
theorem mem_image_iff_of_inverse {f : α → β} {g : β → α} {b : β} {s : Set α} (h₁ : LeftInverse g f) (h₂ : RightInverse g f) : b ∈ f '' s ↔ g b ∈ s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β g : β → α b : β s : Set α h₁ : LeftInverse g f h₂ : Function.RightInverse g f ⊢ b ∈ g ⁻¹' s ↔ g b ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rfl
theorem mem_image_iff_of_inverse {f : α → β} {g : β → α} {b : β} {s : Set α} (h₁ : LeftInverse g f) (h₂ : RightInverse g f) : b ∈ f '' s ↔ g b ∈ s := by rw [image_eq_preimage_of_inverse h₁ h₂];
Mathlib.Data.Set.Image.446_0.IJFiTzmYGOCpPSd
theorem mem_image_iff_of_inverse {f : α → β} {g : β → α} {b : β} {s : Set α} (h₁ : LeftInverse g f) (h₂ : RightInverse g f) : b ∈ f '' s ↔ g b ∈ s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β s : Set α H : Injective f ⊢ Disjoint (f '' s) (f '' sᶜ)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp [disjoint_iff_inf_le, ← image_inter H]
theorem image_compl_subset {f : α → β} {s : Set α} (H : Injective f) : f '' sᶜ ⊆ (f '' s)ᶜ := Disjoint.subset_compl_left <| by
Mathlib.Data.Set.Image.451_0.IJFiTzmYGOCpPSd
theorem image_compl_subset {f : α → β} {s : Set α} (H : Injective f) : f '' sᶜ ⊆ (f '' s)ᶜ
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β s : Set α H : Surjective f ⊢ f '' s ∪ f '' sᶜ = univ
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [← image_union]
theorem subset_image_compl {f : α → β} {s : Set α} (H : Surjective f) : (f '' s)ᶜ ⊆ f '' sᶜ := compl_subset_iff_union.2 <| by
Mathlib.Data.Set.Image.455_0.IJFiTzmYGOCpPSd
theorem subset_image_compl {f : α → β} {s : Set α} (H : Surjective f) : (f '' s)ᶜ ⊆ f '' sᶜ
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t : Set α f : α → β s : Set α H : Surjective f ⊢ f '' (s ∪ sᶜ) = univ
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp [image_univ_of_surjective H]
theorem subset_image_compl {f : α → β} {s : Set α} (H : Surjective f) : (f '' s)ᶜ ⊆ f '' sᶜ := compl_subset_iff_union.2 <| by rw [← image_union]
Mathlib.Data.Set.Image.455_0.IJFiTzmYGOCpPSd
theorem subset_image_compl {f : α → β} {s : Set α} (H : Surjective f) : (f '' s)ᶜ ⊆ f '' sᶜ
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α ⊢ f '' s \ f '' t ⊆ f '' (s \ t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [diff_subset_iff, ← image_union, union_diff_self]
theorem subset_image_diff (f : α → β) (s t : Set α) : f '' s \ f '' t ⊆ f '' (s \ t) := by
Mathlib.Data.Set.Image.465_0.IJFiTzmYGOCpPSd
theorem subset_image_diff (f : α → β) (s t : Set α) : f '' s \ f '' t ⊆ f '' (s \ t)
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s t : Set α ⊢ f '' s ⊆ f '' (t ∪ s)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact image_subset f (subset_union_right t s)
theorem subset_image_diff (f : α → β) (s t : Set α) : f '' s \ f '' t ⊆ f '' (s \ t) := by rw [diff_subset_iff, ← image_union, union_diff_self]
Mathlib.Data.Set.Image.465_0.IJFiTzmYGOCpPSd
theorem subset_image_diff (f : α → β) (s t : Set α) : f '' s \ f '' t ⊆ f '' (s \ t)
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t✝ : Set α hf : Injective f s t : Set α ⊢ f '' s ∆ t = (f '' s) ∆ (f '' t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp_rw [Set.symmDiff_def, image_union, image_diff hf]
theorem image_symmDiff (hf : Injective f) (s t : Set α) : f '' s ∆ t = (f '' s) ∆ (f '' t) := by
Mathlib.Data.Set.Image.481_0.IJFiTzmYGOCpPSd
theorem image_symmDiff (hf : Injective f) (s t : Set α) : f '' s ∆ t = (f '' s) ∆ (f '' t)
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : β → α hf : Surjective f eq : f ⁻¹' s = f ⁻¹' t ⊢ s = t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [← image_preimage_eq s hf, ← image_preimage_eq t hf, eq]
@[simp] theorem preimage_eq_preimage {f : β → α} (hf : Surjective f) : f ⁻¹' s = f ⁻¹' t ↔ s = t := Iff.intro fun eq => by
Mathlib.Data.Set.Image.534_0.IJFiTzmYGOCpPSd
@[simp] theorem preimage_eq_preimage {f : β → α} (hf : Surjective f) : f ⁻¹' s = f ⁻¹' t ↔ s = t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s : Set α t : Set β ⊢ f '' (s ∩ f ⁻¹' t) = f '' s ∩ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
apply Subset.antisymm
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t := by
Mathlib.Data.Set.Image.541_0.IJFiTzmYGOCpPSd
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t
Mathlib_Data_Set_Image
case h₁ α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s : Set α t : Set β ⊢ f '' (s ∩ f ⁻¹' t) ⊆ f '' s ∩ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
calc f '' (s ∩ f ⁻¹' t) ⊆ f '' s ∩ f '' (f ⁻¹' t) := image_inter_subset _ _ _ _ ⊆ f '' s ∩ t := inter_subset_inter_right _ (image_preimage_subset f t)
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t := by apply Subset.antisymm ·
Mathlib.Data.Set.Image.541_0.IJFiTzmYGOCpPSd
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t
Mathlib_Data_Set_Image
case h₂ α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s : Set α t : Set β ⊢ f '' s ∩ t ⊆ f '' (s ∩ f ⁻¹' t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro _ ⟨⟨x, h', rfl⟩, h⟩
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t := by apply Subset.antisymm · calc f '' (s ∩ f ⁻¹' t) ⊆ f '' s ∩ f '' (f ⁻¹' t) := image_inter_subset _ _ _ _ ⊆ f '' s ∩ t := inter_subset_inter_right _ (image_preimage_subset f t) ·
Mathlib.Data.Set.Image.541_0.IJFiTzmYGOCpPSd
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t
Mathlib_Data_Set_Image
case h₂.intro.intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s : Set α t : Set β x : α h' : x ∈ s h : f x ∈ t ⊢ f x ∈ f '' (s ∩ f ⁻¹' t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact ⟨x, ⟨h', h⟩, rfl⟩
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t := by apply Subset.antisymm · calc f '' (s ∩ f ⁻¹' t) ⊆ f '' s ∩ f '' (f ⁻¹' t) := image_inter_subset _ _ _ _ ⊆ f '' s ∩ t := inter_subset_inter_right _ (image_preimage_subset f t) · rintro _ ⟨⟨x, h'...
Mathlib.Data.Set.Image.541_0.IJFiTzmYGOCpPSd
theorem image_inter_preimage (f : α → β) (s : Set α) (t : Set β) : f '' (s ∩ f ⁻¹' t) = f '' s ∩ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s : Set α t : Set β ⊢ f '' (f ⁻¹' t ∩ s) = t ∩ f '' s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp only [inter_comm, image_inter_preimage]
theorem image_preimage_inter (f : α → β) (s : Set α) (t : Set β) : f '' (f ⁻¹' t ∩ s) = t ∩ f '' s := by
Mathlib.Data.Set.Image.551_0.IJFiTzmYGOCpPSd
theorem image_preimage_inter (f : α → β) (s : Set α) (t : Set β) : f '' (f ⁻¹' t ∩ s) = t ∩ f '' s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s : Set α t : Set β ⊢ Set.Nonempty (f '' s ∩ t) ↔ Set.Nonempty (s ∩ f ⁻¹' t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [← image_inter_preimage, nonempty_image_iff]
@[simp] theorem image_inter_nonempty_iff {f : α → β} {s : Set α} {t : Set β} : (f '' s ∩ t).Nonempty ↔ (s ∩ f ⁻¹' t).Nonempty := by
Mathlib.Data.Set.Image.555_0.IJFiTzmYGOCpPSd
@[simp] theorem image_inter_nonempty_iff {f : α → β} {s : Set α} {t : Set β} : (f '' s ∩ t).Nonempty ↔ (s ∩ f ⁻¹' t).Nonempty
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s✝ t✝ : Set α f : α → β s : Set α t : Set β ⊢ f '' (s \ f ⁻¹' t) = f '' s \ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp_rw [diff_eq, ← preimage_compl, image_inter_preimage]
theorem image_diff_preimage {f : α → β} {s : Set α} {t : Set β} : f '' (s \ f ⁻¹' t) = f '' s \ t := by
Mathlib.Data.Set.Image.561_0.IJFiTzmYGOCpPSd
theorem image_diff_preimage {f : α → β} {s : Set α} {t : Set β} : f '' (s \ f ⁻¹' t) = f '' s \ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β hf : Injective f eq : f '' s = f '' t ⊢ s = t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [← preimage_image_eq s hf, ← preimage_image_eq t hf, eq]
theorem image_eq_image {f : α → β} (hf : Injective f) : f '' s = f '' t ↔ s = t := Iff.symm <| (Iff.intro fun eq => eq ▸ rfl) fun eq => by
Mathlib.Data.Set.Image.591_0.IJFiTzmYGOCpPSd
theorem image_eq_image {f : α → β} (hf : Injective f) : f '' s = f '' t ↔ s = t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β hf : Injective f ⊢ f '' s ⊆ f '' t ↔ s ⊆ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
refine' Iff.symm <| (Iff.intro (image_subset f)) fun h => _
theorem image_subset_image_iff {f : α → β} (hf : Injective f) : f '' s ⊆ f '' t ↔ s ⊆ t := by
Mathlib.Data.Set.Image.597_0.IJFiTzmYGOCpPSd
theorem image_subset_image_iff {f : α → β} (hf : Injective f) : f '' s ⊆ f '' t ↔ s ⊆ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β hf : Injective f h : f '' s ⊆ f '' t ⊢ s ⊆ t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rw [← preimage_image_eq s hf, ← preimage_image_eq t hf]
theorem image_subset_image_iff {f : α → β} (hf : Injective f) : f '' s ⊆ f '' t ↔ s ⊆ t := by refine' Iff.symm <| (Iff.intro (image_subset f)) fun h => _
Mathlib.Data.Set.Image.597_0.IJFiTzmYGOCpPSd
theorem image_subset_image_iff {f : α → β} (hf : Injective f) : f '' s ⊆ f '' t ↔ s ⊆ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f✝ : α → β s t : Set α f : α → β hf : Injective f h : f '' s ⊆ f '' t ⊢ f ⁻¹' (f '' s) ⊆ f ⁻¹' (f '' t)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact preimage_mono h
theorem image_subset_image_iff {f : α → β} (hf : Injective f) : f '' s ⊆ f '' t ↔ s ⊆ t := by refine' Iff.symm <| (Iff.intro (image_subset f)) fun h => _ rw [← preimage_image_eq s hf, ← preimage_image_eq t hf]
Mathlib.Data.Set.Image.597_0.IJFiTzmYGOCpPSd
theorem image_subset_image_iff {f : α → β} (hf : Injective f) : f '' s ⊆ f '' t ↔ s ⊆ t
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s ⊢ ⇑σ '' s = s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext i
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α ⊢ i ∈ ⇑σ '' s ↔ i ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
obtain hi | hi := eq_or_ne (σ i) i
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h.inl α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α hi : σ i = i ⊢ i ∈ ⇑σ '' s ↔ i ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
refine' ⟨_, fun h => ⟨i, h, hi⟩⟩
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i obtain hi | hi := eq_or_ne (σ i) i ·
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h.inl α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α hi : σ i = i ⊢ i ∈ ⇑σ '' s → i ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rintro ⟨j, hj, h⟩
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i obtain hi | hi := eq_or_ne (σ i) i · refine' ⟨_, fun h => ⟨i, h, hi⟩⟩
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h.inl.intro.intro α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α hi : σ i = i j : α hj : j ∈ s h : σ j = i ⊢ i ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
rwa [σ.injective (hi.trans h.symm)]
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i obtain hi | hi := eq_or_ne (σ i) i · refine' ⟨_, fun h => ⟨i, h, hi⟩⟩ rintro ⟨j, hj, h⟩
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h.inr α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α hi : σ i ≠ i ⊢ i ∈ ⇑σ '' s ↔ i ∈ s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
refine' iff_of_true ⟨σ.symm i, hs fun h => hi _, σ.apply_symm_apply _⟩ (hs hi)
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i obtain hi | hi := eq_or_ne (σ i) i · refine' ⟨_, fun h => ⟨i, h, hi⟩⟩ rintro ⟨j, hj, h⟩ rwa [σ.i...
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h.inr α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α hi : σ i ≠ i h : σ (σ.symm i) = σ.symm i ⊢ σ i = i
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
convert congr_arg σ h
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i obtain hi | hi := eq_or_ne (σ i) i · refine' ⟨_, fun h => ⟨i, h, hi⟩⟩ rintro ⟨j, hj, h⟩ rwa [σ.i...
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h.e'_2.h.e'_6 α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α hi : σ i ≠ i h : σ (σ.symm i) = σ.symm i ⊢ i = σ (σ.symm i)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact (σ.apply_symm_apply _).symm
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i obtain hi | hi := eq_or_ne (σ i) i · refine' ⟨_, fun h => ⟨i, h, hi⟩⟩ rintro ⟨j, hj, h⟩ rwa [σ.i...
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
case h.e'_3 α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 f : α → β s✝ t s : Set α σ : Equiv.Perm α hs : {a | σ a ≠ a} ⊆ s i : α hi : σ i ≠ i h : σ (σ.symm i) = σ.symm i ⊢ i = σ (σ.symm i)
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
exact (σ.apply_symm_apply _).symm
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s := by ext i obtain hi | hi := eq_or_ne (σ i) i · refine' ⟨_, fun h => ⟨i, h, hi⟩⟩ rintro ⟨j, hj, h⟩ rwa [σ.i...
Mathlib.Data.Set.Image.635_0.IJFiTzmYGOCpPSd
/-- If the only elements outside `s` are those left fixed by `σ`, then mapping by `σ` has no effect. -/ theorem image_perm {s : Set α} {σ : Equiv.Perm α} (hs : { a : α | σ a ≠ a } ⊆ s) : σ '' s = s
Mathlib_Data_Set_Image
α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 s : Set α a : α ⊢ 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
ext t
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s := by
Mathlib.Data.Set.Image.651_0.IJFiTzmYGOCpPSd
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 s : Set α a : α t : Set α ⊢ t ∈ 𝒫 insert a s ↔ t ∈ 𝒫 s ∪ insert a '' 𝒫 s
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
simp_rw [mem_union, mem_image, mem_powerset_iff]
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s := by ext t
Mathlib.Data.Set.Image.651_0.IJFiTzmYGOCpPSd
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s
Mathlib_Data_Set_Image
case h α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 s : Set α a : α t : Set α ⊢ t ⊆ insert a s ↔ t ⊆ s ∨ ∃ x ⊆ s, insert a x = t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
constructor
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s := by ext t simp_rw [mem_union, mem_image, mem_powerset_iff]
Mathlib.Data.Set.Image.651_0.IJFiTzmYGOCpPSd
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s
Mathlib_Data_Set_Image
case h.mp α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 s : Set α a : α t : Set α ⊢ t ⊆ insert a s → t ⊆ s ∨ ∃ x ⊆ s, insert a x = t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
intro h
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s := by ext t simp_rw [mem_union, mem_image, mem_powerset_iff] constructor ·
Mathlib.Data.Set.Image.651_0.IJFiTzmYGOCpPSd
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s
Mathlib_Data_Set_Image
case h.mp α : Type u_1 β : Type u_2 γ : Type u_3 ι : Sort u_4 ι' : Sort u_5 s : Set α a : α t : Set α h : t ⊆ insert a s ⊢ t ⊆ s ∨ ∃ x ⊆ s, insert a x = t
/- Copyright (c) 2014 Jeremy Avigad. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Authors: Jeremy Avigad, Leonardo de Moura -/ import Mathlib.Data.Set.Basic #align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29" /-! # Ima...
by_cases hs : a ∈ t
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s := by ext t simp_rw [mem_union, mem_image, mem_powerset_iff] constructor · intro h
Mathlib.Data.Set.Image.651_0.IJFiTzmYGOCpPSd
/-- The powerset of `{a} ∪ s` is `𝒫 s` together with `{a} ∪ t` for each `t ∈ 𝒫 s`. -/ theorem powerset_insert (s : Set α) (a : α) : 𝒫 insert a s = 𝒫 s ∪ insert a '' 𝒫 s
Mathlib_Data_Set_Image