auxiliary update in basic_2

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / rt_transition / cpm.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/rt_transition/cpm.ma b/matita/matita/contribs/lambdadelta/basic_2/rt_transition/cpm.ma
index d0d19e4a757f10ddc6a73badfe35d69b0564dd72..97cfd31a44e5096dc744e2f55fc528193c7bb303 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/rt_transition/cpm.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/rt_transition/cpm.ma
@@ -121,9 +121,8 @@ lemma cpr_refl: ∀h,G,L. reflexive … (cpm h G L 0).
 
 (* Advanced properties ******************************************************)
 
-lemma cpm_sort_iter (h) (G) (L):
-                    ∀n. n ≤ 1 →
-                    ∀s. ⦃G,L⦄ ⊢ ⋆s ➡ [n,h] ⋆((next h)^n s).
+lemma cpm_sort (h) (G) (L):
+               ∀n. n ≤ 1 → ∀s. ⦃G,L⦄ ⊢ ⋆s ➡[n,h] ⋆((next h)^n s).
 #h #G #L * //
 #n #H #s <(le_n_O_to_eq n) /2 width=1 by le_S_S_to_le/
 qed.
@@ -291,6 +290,22 @@ lemma cpm_inv_cast1: ∀n,h,G,L,V1,U1,U2. ⦃G, L⦄ ⊢ ⓝV1.U1 ➡[n, h] U2 
 ]
 qed-.
 
+(* Advanced inversion lemmas ************************************************)
+
+lemma cpm_inv_appl_sn_decompose (h) (n) (G) (L) (V1) (T1):
+      ∀X2. ⦃G,L⦄ ⊢ ⓐV1.T1 ➡[n,h] X2 →
+      ∃∃T2. ⦃G,L⦄ ⊢ T1 ➡[n,h] T2 & ⦃G,L⦄ ⊢ ⓐV1.T2 ➡[h] X2.
+#h #n #G #L #V1 #T1 #X2 #H
+elim (cpm_inv_appl1 … H) -H *
+[ #V2 #T2 #HV12 #HT12 #H destruct
+  /3 width=3 by cpm_appl, ex2_intro/
+| #p #V2 #W1 #W2 #U1 #U2 #HV12 #HW12 #HU12 #H1 #H2 destruct
+  /3 width=5 by cpm_beta, cpm_bind, ex2_intro/
+| #p #V2 #V0 #W1 #W2 #U1 #U2 #HV12 #HV20 #HW12 #HU12 #H1 #H2 destruct
+  /3 width=5 by cpm_theta, cpm_bind, ex2_intro/
+]
+qed-.
+
 (* Basic forward lemmas *****************************************************)
 
 (* Basic_2A1: includes: cpr_fwd_bind1_minus *)