Theorem: Finset.memberFamily_induction_on
File: Mathlib/Combinatorics/SetFamily/Compression/Down.lean

Proof steps:
state_before: α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
𝒜 : Finset (Finset α)
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
⊢ p 𝒜
state_after: α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
𝒜 : Finset (Finset α)
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
u : Finset α := 𝒜.sup id
⊢ p 𝒜
tactic: set u := 𝒜.sup id
state_before: α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
𝒜 : Finset (Finset α)
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
u : Finset α := 𝒜.sup id
⊢ p 𝒜
state_after: α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
𝒜 : Finset (Finset α)
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
u : Finset α := 𝒜.sup id
hu : ∀ s ∈ 𝒜, s ⊆ u
⊢ p 𝒜
tactic: have hu : ∀ s ∈ 𝒜, s ⊆ u := fun s ↦ le_sup (f := id)
state_before: α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
𝒜 : Finset (Finset α)
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
u : Finset α := 𝒜.sup id
hu : ∀ s ∈ 𝒜, s ⊆ u
⊢ p 𝒜
state_after: α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
𝒜 : Finset (Finset α)
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
u : Finset α
hu : ∀ s ∈ 𝒜, s ⊆ u
⊢ p 𝒜
tactic: clear_value u
state_before: α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
𝒜 : Finset (Finset α)
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
u : Finset α
hu : ∀ s ∈ 𝒜, s ⊆ u
⊢ p 𝒜
state_after: case empty
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a : α
p : Finset (Finset α) → Prop
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
𝒜 : Finset (Finset α)
hu : ∀ s ∈ 𝒜, s ⊆ ∅
⊢ p 𝒜

case insert
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a✝¹ : α
p : Finset (Finset α) → Prop
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
a : α
u : Finset α
a✝ : a ∉ u
ih : ∀ (𝒜 : Finset (Finset α)), (∀ s ∈ 𝒜, s ⊆ u) → p 𝒜
𝒜 : Finset (Finset α)
hu : ∀ s ∈ 𝒜, s ⊆ insert a u
⊢ p 𝒜
tactic: induction' u using Finset.induction with a u _ ih generalizing 𝒜
state_before: case insert
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a✝¹ : α
p : Finset (Finset α) → Prop
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
a : α
u : Finset α
a✝ : a ∉ u
ih : ∀ (𝒜 : Finset (Finset α)), (∀ s ∈ 𝒜, s ⊆ u) → p 𝒜
𝒜 : Finset (Finset α)
hu : ∀ s ∈ 𝒜, s ⊆ insert a u
⊢ p 𝒜
state_after: case insert.refine_1
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a✝¹ : α
p : Finset (Finset α) → Prop
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
a : α
u : Finset α
a✝ : a ∉ u
ih : ∀ (𝒜 : Finset (Finset α)), (∀ s ∈ 𝒜, s ⊆ u) → p 𝒜
𝒜 : Finset (Finset α)
hu : ∀ s ∈ 𝒜, s ⊆ insert a u
⊢ ∀ s ∈ nonMemberSubfamily a 𝒜, s ⊆ u

case insert.refine_2
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ ℬ : Finset (Finset α)
s : Finset α
a✝¹ : α
p : Finset (Finset α) → Prop
empty : p ∅
singleton_empty : p {∅}
subfamily : ∀ (a : α) ⦃𝒜 : Finset (Finset α)⦄, p (nonMemberSubfamily a 𝒜) → p (memberSubfamily a 𝒜) → p 𝒜
a : α
u : Finset α
a✝ : a ∉ u
ih : ∀ (𝒜 : Finset (Finset α)), (∀ s ∈ 𝒜, s ⊆ u) → p 𝒜
𝒜 : Finset (Finset α)
hu : ∀ s ∈ 𝒜, s ⊆ insert a u
⊢ ∀ s ∈ memberSubfamily a 𝒜, s ⊆ u
tactic: refine subfamily a (ih _ ?_) (ih _ ?_)