From Undecidability.L Require Export Util.L_facts.
From Undecidability.L.Tactics Require Import LTactics GenEncode.

MetaCoq Run (tmGenEncodeInj "unit_enc" unit).
Hint Resolve unit_enc_correct : Lrewrite.

Lemma size_unit_enc : size(enc tt) = 2.
Proof. reflexivity. Qed.