- some additions and corrections

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

diff --git a/matita/matita/contribs/lambda_delta/basic_2/computation/fprs_cprs.ma b/matita/matita/contribs/lambda_delta/basic_2/computation/fprs_cprs.ma
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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||M||                                                             *)
+(*      ||A||       A project by Andrea Asperti                           *)
+(*      ||T||                                                             *)
+(*      ||I||       Developers:                                           *)
+(*      ||T||         The HELM team.                                      *)
+(*      ||A||         http://helm.cs.unibo.it                             *)
+(*      \   /                                                             *)
+(*       \ /        This file is distributed under the terms of the       *)
+(*        v         GNU General Public License Version 2                  *)
+(*                                                                        *)
+(**************************************************************************)
+
+include "basic_2/reducibility/fpr_cpr.ma".
+include "basic_2/computation/cprs.ma".
+include "basic_2/computation/fprs.ma".
+
+(* CONTEXT-FREE PARALLEL COMPUTATION ON CLOSURES ****************************)
+
+(* Properties on context-sensitive parallel computation for terms ***********)
+
+lemma cprs_fprs: ∀L,T1,T2. L ⊢ T1 ➡* T2 → ⦃L, T1⦄ ➡* ⦃L, T2⦄.
+#L #T1 #T2 #H @(cprs_ind … H) -T2 // /3 width=4/
+qed.
+(*
+(* Advanced propertis *******************************************************)
+
+lamma fpr_bind_sn: ∀L1,L2,V1,V2. ⦃L1, V1⦄ ➡ ⦃L2, V2⦄ → ∀T1,T2. T1 ➡ T2 →
+                   ∀a,I. ⦃L1, ⓑ{a,I}V1.T1⦄ ➡ ⦃L2, ⓑ{a,I}V2.T2⦄.
+#L1 #L2 #V1 #V2 #H #T1 #T2 #HT12 #a #I
+elim (fpr_inv_all … H) /3 width=4/
+qed.
+
+(* Advanced forward lemmas **************************************************)
+
+lamma fpr_fwd_shift_bind_minus: ∀I1,I2,L1,L2,V1,V2,T1,T2.
+                                ⦃L1, -ⓑ{I1}V1.T1⦄ ➡ ⦃L2, -ⓑ{I2}V2.T2⦄ →
+                                ⦃L1, V1⦄ ➡ ⦃L2, V2⦄ ∧ I1 = I2.
+* #I2 #L1 #L2 #V1 #V2 #T1 #T2 #H
+elim (fpr_inv_all … H) -H #L #HL1 #H #HL2
+[ elim (cpr_inv_abbr1 … H) -H *
+  [ #V #V0 #T #HV1 #HV0 #_ #H destruct /4 width=4/
+  | #T #_ #_ #H destruct
+  ]
+| elim (cpr_inv_abst1 … H Abst V2) -H
+  #V #T #HV1 #_ #H destruct /3 width=4/
+]
+qed-.
+
+(* Advanced inversion lemmas ************************************************)
+
+lamma fpr_inv_pair1: ∀I,K1,L2,V1,T1,T2. ⦃K1.ⓑ{I}V1, T1⦄ ➡ ⦃L2, T2⦄ →
+                     ∃∃K2,V2. ⦃K1, V1⦄  ➡ ⦃K2, V2⦄ &
+                              ⦃K1, -ⓑ{I}V1.T1⦄ ➡ ⦃K2, -ⓑ{I}V2.T2⦄  &
+                              L2 = K2.ⓑ{I}V2.
+#I1 #K1 #X #V1 #T1 #T2 #H
+elim (fpr_fwd_pair1 … H) -H #I2 #K2 #V2 #HT12 #H destruct
+elim (fpr_fwd_shift_bind_minus … HT12) #HV12 #H destruct /2 width=5/
+qed-.
+
+lamma fpr_inv_pair3: ∀I,L1,K2,V2,T1,T2. ⦃L1, T1⦄ ➡ ⦃K2.ⓑ{I}V2, T2⦄ →
+                     ∃∃K1,V1. ⦃K1, V1⦄  ➡ ⦃K2, V2⦄ &
+                              ⦃K1, -ⓑ{I}V1.T1⦄ ➡ ⦃K2, -ⓑ{I}V2.T2⦄  &
+                              L1 = K1.ⓑ{I}V1.
+#I2 #X #K2 #V2 #T1 #T2 #H
+elim (fpr_fwd_pair3 … H) -H #I1 #K1 #V1 #HT12 #H destruct
+elim (fpr_fwd_shift_bind_minus … HT12) #HV12 #H destruct /2 width=5/
+qed-.
+*)