bug fix in the context reduction rule for cast (cpm)

[helm.git] / matita / matita / contribs / lambdadelta / ground_2 / steps / rtc_isrt.ma

diff --git a/matita/matita/contribs/lambdadelta/ground_2/steps/rtc_isrt.ma b/matita/matita/contribs/lambdadelta/ground_2/steps/rtc_isrt.ma
index ced83577ac246dddcb5a4edaff326317b8606908..9c988abea63f85bd33a65e7d05b191bfe96b1244 100644 (file)
--- a/matita/matita/contribs/lambdadelta/ground_2/steps/rtc_isrt.ma
+++ b/matita/matita/contribs/lambdadelta/ground_2/steps/rtc_isrt.ma
@@ -34,6 +34,11 @@ lemma isr_10: 𝐑𝐓⦃0, 𝟙𝟘⦄.
 lemma isrt_01: 𝐑𝐓⦃1, 𝟘𝟙⦄.
 /2 width=3 by ex1_2_intro/ qed.
 
+lemma isrt_eq_t_trans: ∀n,c1,c2. 𝐑𝐓⦃n, c1⦄ → eq_t c1 c2 → 𝐑𝐓⦃n, c2⦄.
+#n #c1 #c2 * #ri1 #rs1 #H destruct
+#H elim (eq_t_inv_dx … H) -H /2 width=3 by ex1_2_intro/
+qed-.
+
 (* Basic inversion properties ***********************************************)
 
 lemma isrt_inv_00: ∀n. 𝐑𝐓⦃n, 𝟘𝟘⦄ → 0 = n.
@@ -50,6 +55,10 @@ qed-.
 
 (* Main inversion properties ************************************************)
 
-theorem isrt_mono: ∀n1,n2,c. 𝐑𝐓⦃n1, c⦄ → 𝐑𝐓⦃n2, c⦄ → n1 = n2.
+theorem isrt_inj: ∀n1,n2,c. 𝐑𝐓⦃n1, c⦄ → 𝐑𝐓⦃n2, c⦄ → n1 = n2.
 #n1 #n2 #c * #ri1 #rs1 #H1 * #ri2 #rs2 #H2 destruct //
 qed-.
+
+theorem isrt_mono: ∀n,c1,c2. 𝐑𝐓⦃n, c1⦄ → 𝐑𝐓⦃n, c2⦄ → eq_t c1 c2.
+#n #c1 #c2 * #ri1 #rs1 #H1 * #ri2 #rs2 #H2 destruct //
+qed-.