matita/matita/contribs/lambdadelta/basic_2/i_dynamic/ntas_ntas.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
   7 (*      ||T||         The HELM team.                                      *)
   8 (*      ||A||         http://helm.cs.unibo.it                             *)
   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 include "basic_2/i_dynamic/ntas_preserve.ma".
  16
  17 (* ITERATED NATIVE TYPE ASSIGNMENT FOR TERMS ********************************)
  18
  19 (* Main properties **********************************************************)
  20
  21 theorem ntas_trans (h) (a) (G) (L) (T0):
  22         ∀n1,T1. ❪G,L❫ ⊢ T1 :*[h,a,n1] T0 →
  23         ∀n2,T2. ❪G,L❫ ⊢ T0 :*[h,a,n2] T2 → ❪G,L❫ ⊢ T1 :*[h,a,n1+n2] T2.
  24 #h #a #G #L #T0 #n1 #T1 * #X1 #HT0 #HT1 #H01 #H11 #n2 #T2 * #X2 #HT2 #_ #H22 #H02
  25 elim (cnv_cpms_conf … HT0 … H01 … H02) -T0 <minus_O_n <minus_n_O #X0 #H10 #H20
  26 /3 width=5 by ntas_intro, cpms_trans/
  27 qed-.