tauto
γ α : Program
ℓ : TP (∗α)
head✝ : Program
tail✝ αs : List Program
αs_in : αs ∈ List.filter (fun x => x != []) (P α fun x => ℓ ⟨↑x, ⋯⟩)
def_δ : αs ++ [∗α] = head✝ :: tail✝
γ_not_in : γ ∉ αs
γ_in : γ ∈ αs ∨ γ = (∗α)
⊢ γ = (∗α)
no goals