matita/matita/contribs/lambdadelta/alpha_1/syntax/item.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 (* THE FORMAL SYSTEM α: MATITA SOURCE FILES
  16  * Initial invocation : - Patience on me to gain peace and perfection! -
  17  * Developed since    : 2014 July 25
  18  *)
  19
  20 include "ground_2/lib/bool.ma".
  21 include "ground_2/lib/arith.ma".
  22
  23 (* ITEMS ********************************************************************)
  24
  25 (* unary items *)
  26 inductive item1: Type[0] ≝
  27    | Char: nat → item1 (* character: starting at 0 *)
  28    | LRef: nat → item1 (* reference by index: starting at 0 *)
  29    | GRef: nat → item1 (* reference by position: starting at 0 *)
  30    | Decl:       item1 (* global abstraction *)
  31 .
  32
  33 (* binary items *)
  34 inductive item2: Type[0] ≝
  35    | Abst:        item2 (* local abstraction *)
  36    | Abbr: bool → item2 (* local (Ⓣ) or global (Ⓕ) abbreviation *)
  37    | Proj: bool → item2 (* local (Ⓣ) or global (Ⓕ) projection *)
  38 .