Can we regard the following function as proof? Can we read it as conversion of statement ((P→⊥)→⊥) to ((⊥→⊥)→⊥) with last ⊥ encoded by nontermination? {-# OPTIONS --no-termination-check #-} module DoubleNegation where data ⊥ : Set where ⊥⊥→⊥ : {P : Set} → ((P → ⊥) → ⊥) → (P → ⊥) ⊥⊥→⊥ {P} double = h where h : P → ⊥ h P = double h