(* * Classical Natural Deduction *)
From Undecidability.FOL Require Export PCPb_to_FOL.
From Undecidability.Synthetic Require Import Definitions DecidabilityFacts EnumerabilityFacts ReducibilityFacts.
(* ** Double Negation Translation *)
Implicit Type b : falsity_flag.
Definition cprv := @prv _ _ falsity_on class.
Instance iUnit (P : Prop) : interp unit.

Lemma MND_CND A (phi : form falsity_off) :
A ⊢M phi -> map cast A ⊢C cast phi.