2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department of the University of Bologna, Italy.
7 ||A|| This file is distributed under the terms of the
8 \ / GNU General Public License Version 2
10 V_______________________________________________________________ *)
12 (* THE FORMAL SYSTEM λδ - MATITA SOURCE SCRIPTS
13 * Specification started: 2011 April 17
14 * - Patience on me so that I gain peace and perfection! -
15 * [ suggested invocation to start formal specifications with ]
18 include "lambda-delta/ground.ma".
20 (* BINARY ITEMS *************************************************************)
23 inductive item2: Type[0] ≝
24 | Abbr: item2 (* abbreviation *)
25 | Abst: item2 (* abstraction *)
26 | Appl: item2 (* application *)
27 | Cast: item2 (* explicit type annotation *)
30 (* reduction-related categorization *****************************************)
32 (* binary items entitled for zeta-reduction *)
33 definition zable2 ≝ λI. I = Abbr ∨ I = Cast.
35 interpretation "is entitled for zeta-reduction" 'Zeta I = (zable2 I).
37 (* binary items entitled for theta reduction *)
38 definition thable2 ≝ λI. I = Abbr.
40 interpretation "is entitled for theta-reduction" 'Theta I = (thable2 I).