matita/matita/contribs/lambdadelta/static_2/static/lsuba.ma

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  14
  15 include "ground/xoa/ex_5_4.ma".
  16 include "static_2/notation/relations/lrsubeqa_3.ma".
  17 include "static_2/static/aaa.ma".
  18
  19 (* RESTRICTED REFINEMENT FOR ATOMIC ARITY ASSIGNMENT ************************)
  20
  21 inductive lsuba (G:genv): relation lenv ≝
  22 | lsuba_atom: lsuba G (⋆) (⋆)
  23 | lsuba_bind: ∀I,L1,L2. lsuba G L1 L2 → lsuba G (L1.ⓘ[I]) (L2.ⓘ[I])
  24 | lsuba_beta: ∀L1,L2,W,V,A. ❨G,L1❩ ⊢ ⓝW.V ⁝ A → ❨G,L2❩ ⊢ W ⁝ A →
  25               lsuba G L1 L2 → lsuba G (L1.ⓓⓝW.V) (L2.ⓛW)
  26 .
  27
  28 interpretation
  29   "local environment refinement (atomic arity assignment)"
  30   'LRSubEqA G L1 L2 = (lsuba G L1 L2).
  31
  32 (* Basic inversion lemmas ***************************************************)
  33
  34 fact lsuba_inv_atom1_aux: ∀G,L1,L2. G ⊢ L1 ⫃⁝ L2 → L1 = ⋆ → L2 = ⋆.
  35 #G #L1 #L2 * -L1 -L2
  36 [ //
  37 | #I #L1 #L2 #_ #H destruct
  38 | #L1 #L2 #W #V #A #_ #_ #_ #H destruct
  39 ]
  40 qed-.
  41
  42 lemma lsuba_inv_atom1: ∀G,L2. G ⊢ ⋆ ⫃⁝ L2 → L2 = ⋆.
  43 /2 width=4 by lsuba_inv_atom1_aux/ qed-.
  44
  45 fact lsuba_inv_bind1_aux: ∀G,L1,L2. G ⊢ L1 ⫃⁝ L2 → ∀I,K1. L1 = K1.ⓘ[I] →
  46                           (∃∃K2. G ⊢ K1 ⫃⁝ K2 & L2 = K2.ⓘ[I]) ∨
  47                           ∃∃K2,W,V,A. ❨G,K1❩ ⊢ ⓝW.V ⁝ A & ❨G,K2❩ ⊢ W ⁝ A &
  48                                       G ⊢ K1 ⫃⁝ K2 & I = BPair Abbr (ⓝW.V) & L2 = K2.ⓛW.
  49 #G #L1 #L2 * -L1 -L2
  50 [ #J #K1 #H destruct
  51 | #I #L1 #L2 #HL12 #J #K1 #H destruct /3 width=3 by ex2_intro, or_introl/
  52 | #L1 #L2 #W #V #A #HV #HW #HL12 #J #K1 #H destruct /3 width=9 by ex5_4_intro, or_intror/
  53 ]
  54 qed-.
  55
  56 lemma lsuba_inv_bind1: ∀I,G,K1,L2. G ⊢ K1.ⓘ[I] ⫃⁝ L2 →
  57                        (∃∃K2. G ⊢ K1 ⫃⁝ K2 & L2 = K2.ⓘ[I]) ∨
  58                        ∃∃K2,W,V,A. ❨G,K1❩ ⊢ ⓝW.V ⁝ A & ❨G,K2❩ ⊢ W ⁝ A & G ⊢ K1 ⫃⁝ K2 &
  59                                    I = BPair Abbr (ⓝW.V) & L2 = K2.ⓛW.
  60 /2 width=3 by lsuba_inv_bind1_aux/ qed-.
  61
  62 fact lsuba_inv_atom2_aux: ∀G,L1,L2. G ⊢ L1 ⫃⁝ L2 → L2 = ⋆ → L1 = ⋆.
  63 #G #L1 #L2 * -L1 -L2
  64 [ //
  65 | #I #L1 #L2 #_ #H destruct
  66 | #L1 #L2 #W #V #A #_ #_ #_ #H destruct
  67 ]
  68 qed-.
  69
  70 lemma lsuba_inv_atom2: ∀G,L1. G ⊢ L1 ⫃⁝ ⋆ → L1 = ⋆.
  71 /2 width=4 by lsuba_inv_atom2_aux/ qed-.
  72
  73 fact lsuba_inv_bind2_aux: ∀G,L1,L2. G ⊢ L1 ⫃⁝ L2 → ∀I,K2. L2 = K2.ⓘ[I] →
  74                           (∃∃K1. G ⊢ K1 ⫃⁝ K2 & L1 = K1.ⓘ[I]) ∨
  75                           ∃∃K1,V,W,A. ❨G,K1❩ ⊢ ⓝW.V ⁝ A & ❨G,K2❩ ⊢ W ⁝ A &
  76                                        G ⊢ K1 ⫃⁝ K2 & I = BPair Abst W & L1 = K1.ⓓⓝW.V.
  77 #G #L1 #L2 * -L1 -L2
  78 [ #J #K2 #H destruct
  79 | #I #L1 #L2 #HL12 #J #K2 #H destruct /3 width=3 by ex2_intro, or_introl/
  80 | #L1 #L2 #W #V #A #HV #HW #HL12 #J #K2 #H destruct /3 width=9 by ex5_4_intro, or_intror/
  81 ]
  82 qed-.
  83
  84 lemma lsuba_inv_bind2: ∀I,G,L1,K2. G ⊢ L1 ⫃⁝ K2.ⓘ[I] →
  85                        (∃∃K1. G ⊢ K1 ⫃⁝ K2 & L1 = K1.ⓘ[I]) ∨
  86                        ∃∃K1,V,W,A. ❨G,K1❩ ⊢ ⓝW.V ⁝ A & ❨G,K2❩ ⊢ W ⁝ A & G ⊢ K1 ⫃⁝ K2 &
  87                                    I = BPair Abst W & L1 = K1.ⓓⓝW.V.
  88 /2 width=3 by lsuba_inv_bind2_aux/ qed-.
  89
  90 (* Basic properties *********************************************************)
  91
  92 lemma lsuba_refl: ∀G,L. G ⊢ L ⫃⁝ L.
  93 #G #L elim L -L /2 width=1 by lsuba_atom, lsuba_bind/
  94 qed.