Theorem: Computation.terminates_parallel.aux
File: Mathlib/Data/Seq/Parallel.lean

Proof steps:
state_before: α : Type u
β : Type v
⊢ ∀ {l : List (Computation α)} {S : WSeq (Computation α)} {c : Computation α},
    c ∈ l → c.Terminates → (corec parallel.aux1 (l, S)).Terminates
state_after: α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
⊢ ∀ {l : List (Computation α)} {S : WSeq (Computation α)} {c : Computation α},
    c ∈ l → c.Terminates → (corec parallel.aux1 (l, S)).Terminates
tactic: have lem1 :
    ∀ l S, (∃ a : α, parallel.aux2 l = Sum.inl a) → Terminates (corec parallel.aux1 (l, S)) := by
    intro l S e
    cases' e with a e
    have : corec parallel.aux1 (l, S) = return a := by
      apply destruct_eq_pure
      simp only [parallel.aux1, rmap, corec_eq]
      rw [e]
    rw [this]
    -- Porting note: This line is required.
    exact ret_terminates a
state_before: α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
⊢ ∀ {l : List (Computation α)} {S : WSeq (Computation α)} {c : Computation α},
    c ∈ l → c.Terminates → (corec parallel.aux1 (l, S)).Terminates
state_after: α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
l : List (Computation α)
S : WSeq (Computation α)
c : Computation α
m : c ∈ l
T : c.Terminates
⊢ (corec parallel.aux1 (l, S)).Terminates
tactic: intro l S c m T
state_before: α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
l : List (Computation α)
S : WSeq (Computation α)
c : Computation α
m : c ∈ l
T : c.Terminates
⊢ (corec parallel.aux1 (l, S)).Terminates
state_after: α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
c : Computation α
T : c.Terminates
⊢ ∀ {l : List (Computation α)} {S : WSeq (Computation α)}, c ∈ l → (corec parallel.aux1 (l, S)).Terminates
tactic: revert l S
state_before: α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
c : Computation α
T : c.Terminates
⊢ ∀ {l : List (Computation α)} {S : WSeq (Computation α)}, c ∈ l → (corec parallel.aux1 (l, S)).Terminates
state_after: α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
c : Computation α
T : c.Terminates
⊢ ∀ (a : α) {l : List (Computation α)} {S : WSeq (Computation α)}, pure a ∈ l → (corec parallel.aux1 (l, S)).Terminates

α : Type u
β : Type v
lem1 :
  ∀ (l : List (Computation α)) (S : WSeq (Computation α)),
    (∃ a, parallel.aux2 l = Sum.inl a) → (corec parallel.aux1 (l, S)).Terminates
c : Computation α
T : c.Terminates
⊢ ∀ (s : Computation α),
    (∀ {l : List (Computation α)} {S : WSeq (Computation α)}, s ∈ l → (corec parallel.aux1 (l, S)).Terminates) →
      ∀ {l : List (Computation α)} {S : WSeq (Computation α)}, s.think ∈ l → (corec parallel.aux1 (l, S)).Terminates
tactic: apply @terminatesRecOn _ _ c T _ _