- we polarized binders to control zeta reduction

[helm.git] / matita / matita / contribs / lambda_delta / basic_2 / computation / xprs.ma

diff --git a/matita/matita/contribs/lambda_delta/basic_2/computation/xprs.ma b/matita/matita/contribs/lambda_delta/basic_2/computation/xprs.ma
index 775e136cbb884e29d1ec6940b3d24fe43f0be03a..2eb8903e1e99b4f7126029d5308a58591235aa0a 100644 (file)
--- a/matita/matita/contribs/lambda_delta/basic_2/computation/xprs.ma
+++ b/matita/matita/contribs/lambda_delta/basic_2/computation/xprs.ma
@@ -45,14 +45,16 @@ qed-.
 lemma xprs_refl: ∀h,g,L,T. ⦃h, L⦄ ⊢ T ➸*[g] T.
 /2 width=1/ qed.
 
-lemma xprs_strap1: ∀h,g,L,T1,T,T2.
+axiom xprs_strap1: ∀h,g,L,T1,T,T2.
                    ⦃h, L⦄ ⊢ T1 ➸*[g] T → ⦃h, L⦄ ⊢ T ➸[g] T2 → ⦃h, L⦄ ⊢ T1 ➸*[g] T2.
+(**) (* NTypeChecker failure
 /2 width=3/ qed.
-
-lemma xprs_strap2: ∀h,g,L,T1,T,T2.
+*)
+axiom xprs_strap2: ∀h,g,L,T1,T,T2.
                    ⦃h, L⦄ ⊢ T1 ➸[g] T → ⦃h, L⦄ ⊢ T ➸*[g] T2 → ⦃h, L⦄ ⊢ T1 ➸*[g] T2.
+(**) (* NTypeChecker failure
 /2 width=3/ qed.
-
+*)
 (* Basic inversion lemmas ***************************************************)
 (*
 axiom xprs_inv_cnf1: ∀L,T,U. L ⊢ T ➡* U → L ⊢ 𝐍⦃T⦄ → T = U.