matita/matita/contribs/lambdadelta/basic_2/rt_computation/cprs_drops.ma

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  14
  15 include "basic_2/rt_computation/cpms_drops.ma".
  16
  17 (* CONTEXT-SENSITIVE PARALLEL R-COMPUTATION FOR TERMS ***********************)
  18
  19 (* Advanced inversion lemmas ************************************************)
  20
  21 (* Basic_1: was: pr3_gen_lref *)
  22 (* Basic_2A1: was: cprs_inv_lref1 *)
  23 lemma cprs_inv_lref1_drops (h) (G): ∀L,T2,i. ❪G,L❫ ⊢ #i ➡*[h,0] T2 →
  24                                     ∨∨ T2 = #i
  25                                      | ∃∃K,V1,T1. ⇩[i] L ≘ K.ⓓV1 & ❪G,K❫ ⊢ V1 ➡*[h,0] T1 &
  26                                                   ⇧[↑i] T1 ≘ T2.
  27 #h #G #L #T2 #i #H elim (cpms_inv_lref1_drops … H) -H *
  28 [ /2 width=1 by or_introl/
  29 | /3 width=6 by ex3_3_intro, or_intror/
  30 | #m #K #V #V2 #_ #_ #_ #H destruct
  31 ]
  32 qed-.