matita/matita/contribs/lambdadelta/basic_2A/etc/cny/cpzs.etc

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  14
  15 include "basic_2/notation/relations/pdeltaconvstar_6.ma".
  16 include "basic_2/substitution/cpye_lift.ma".
  17
  18 (* CONTEXT-SENSITIVE EXTENDED DELTA-EQUIVALENCE FOR TERMS *******************)
  19
  20 definition cpzs: ynat → ynat → relation4 genv lenv term term ≝
  21                  λd,e,G,L,T1,T2.
  22                  ∃∃T. ⦃G, L⦄ ⊢ T1 ▶*[d, e] 𝐍⦃T⦄ & ⦃G, L⦄ ⊢ T2 ▶*[d, e] 𝐍⦃T⦄.
  23
  24 interpretation "context-sensitive extended delta-equivalence (term)"
  25    'PDeltaConvStar G L T1 d e T2 = (cpzs d e G L T1 T2).
  26
  27 (* Basic properties **********************************************************)
  28
  29 lemma cpye_div: ∀G,L,T1,T,d,e.  ⦃G, L⦄ ⊢ T1 ▶*[d, e] 𝐍⦃T⦄ →
  30                 ∀T2. ⦃G, L⦄ ⊢ T2 ▶*[d, e] 𝐍⦃T⦄ → ⦃G, L⦄ ⊢ T1 ◆*[d, e] T2.
  31 /2 width=3 by ex2_intro/ qed.
  32
  33 lemma cpzs_refl: ∀G,L,d,e. reflexive … (cpzs d e G L).
  34 #G #L #d #e #T elim (cpye_total G L T d e) /2 width=3 by cpye_div/
  35 qed.
  36
  37 lemma cpzs_bind: ∀G,L,V1,V2,d,e. ⦃G, L⦄ ⊢ V1 ◆*[d, e] V2 →
  38                  ∀I,T1,T2. ⦃G, L.ⓑ{I}V1⦄ ⊢ T1 ◆*[⫯d, e] T2 →
  39                  ∀a. ⦃G, L⦄ ⊢ ⓑ{a,I}V1.T1 ◆*[d, e] ⓑ{a,I}V2.T2.
  40 #G #L #V1 #V2 #d #e * #V #HV1 #HV2 #I #T1 #T2 *
  41 /5 width=10 by cpye_div, cpye_bind, leqy_cpye_trans, cny_bind, lsuby_succ/
  42 qed.
  43
  44 lemma cpzs_flat: ∀G,L,V1,V2,d,e. ⦃G, L⦄ ⊢ V1 ◆*[d, e] V2 →
  45                  ∀T1,T2. ⦃G, L⦄ ⊢ T1 ◆*[d, e] T2 →
  46                  ∀I. ⦃G, L⦄ ⊢ ⓕ{I}V1.T1 ◆*[d, e] ⓕ{I}V2.T2.
  47 #G #L #V1 #V2 #d #e * #V #HV1 #HV2 #T1 #T2 *
  48 /3 width=5 by cpye_div, cpye_flat, cny_flat/
  49 qed.
  50
  51 (* Basic inversion lemmas ***************************************************)
  52
  53 lemma cpzs_inv_sort: ∀G,L,d,e,k1,k2. ⦃G, L⦄ ⊢ ⋆k1 ◆*[d, e] ⋆k2 → k1 = k2.
  54 #G #L #d #e #k1 #k2 * #X #H1 #H2
  55 lapply (cpye_inv_sort1 … H1) -H1 #H1
  56 lapply (cpye_inv_sort1 … H2) -H2 #H2
  57 destruct //
  58 qed-.
  59
  60 lemma cpzs_inv_bind: ∀a1,a2,I1,I2,G,L,V1,V2,T1,T2,d,e. ⦃G, L⦄ ⊢ ⓑ{a1,I1}V1.T1 ◆*[d, e] ⓑ{a2,I2}V2.T2 →
  61                      ∧∧ a1 = a2 & I1 = I2
  62                       & ⦃G, L⦄ ⊢ V1 ◆*[d, e] V2 & ⦃G, L.ⓑ{I1}V1⦄ ⊢ T1 ◆*[⫯d, e] T2.
  63 #a1 #a2 #I1 #I2 #G #L #V1 #V2 #T1 #T2 #d #e * #X #H1 #H2
  64 elim (cpye_inv_bind1 … H1) -H1 #V2 #T2 #HV12 #HT12 #H1
  65 elim (cpye_inv_bind1 … H2) -H2 #W2 #U2 #HW12 #HU12 #H2
  66 destruct /5 width=8 by cpye_div, leqy_cpye_trans, lsuby_succ, and4_intro/
  67 qed-.
  68
  69 lemma cpzs_inv_flat: ∀I1,I2,G,L,V1,V2,T1,T2,d,e. ⦃G, L⦄ ⊢ ⓕ{I1}V1.T1 ◆*[d, e] ⓕ{I2}V2.T2 →
  70                      ∧∧ I1 = I2
  71                       & ⦃G, L⦄ ⊢ V1 ◆*[d, e] V2 & ⦃G, L⦄ ⊢ T1 ◆*[d, e] T2.
  72 #I1 #I2 #G #L #V1 #V2 #T1 #T2 #d #e * #X #H1 #H2
  73 elim (cpye_inv_flat1 … H1) -H1 #V2 #T2 #HV12 #HT12 #H1
  74 elim (cpye_inv_flat1 … H2) -H2 #W2 #U2 #HW12 #HU12 #H2
  75 destruct /3 width=3 by cpye_div, and3_intro/
  76 qed-.
  77
  78 lemma cpzs_inv_flat_bind: ∀a2,I1,I2,G,L,V1,V2,T1,T2,d,e. ⦃G, L⦄ ⊢ ⓕ{I1}V1.T1 ◆*[d, e] ⓑ{a2,I2}V2.T2 → ⊥.
  79 #a2 #I1 #I2 #G #L #V1 #V2 #T1 #T2 #d #e * #X #H1 #H2
  80 elim (cpye_inv_flat1 … H1) -H1 #V2 #T2 #HV12 #HT12 #H1
  81 elim (cpye_inv_bind1 … H2) -H2 #W2 #U2 #HW12 #HU12 #H2
  82 destruct
  83 qed-.