proposition: Theorem Ropp_involutive_trivial_realizer : forall e, (λ"_" λ"_" λ"x" λ"f" "f" @ "x")↓e ⊩ ∀x, x ≤ -(-x).
proof: Proof. unfold Rle. Ksolve. apply Qcopp_le_compat; eok. rewrite Qcopp_involutive. eapply sub_term. eok. now apply (↓x). Qed.
imports: QArith Psatz ClassicalRealizability.Kbase ClassicalRealizability.Rationals