branch for universe

[helm.git] / matita / contribs / LOGIC / datatypes_defs / Proof.ma

diff --git a/matita/contribs/LOGIC/datatypes_defs/Proof.ma b/matita/contribs/LOGIC/datatypes_defs/Proof.ma
new file mode 100644 (file)
index 0000000..1f56cd9
--- /dev/null
+++ b/matita/contribs/LOGIC/datatypes_defs/Proof.ma
@@ -0,0 +1,31 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||M||                                                             *)
+(*      ||A||       A project by Andrea Asperti                           *)
+(*      ||T||                                                             *)
+(*      ||I||       Developers:                                           *)
+(*      ||T||         The HELM team.                                      *)
+(*      ||A||         http://helm.cs.unibo.it                             *)
+(*      \   /                                                             *)
+(*       \ /        This file is distributed under the terms of the       *)
+(*        v         GNU General Public License Version 2                  *)
+(*                                                                        *)
+(**************************************************************************)
+
+
+
+(* PROOFS
+   - Naming policy:
+     - proofs: p q r s
+*)
+
+include "preamble0.ma".
+
+inductive Proof: Type \def
+   | lref: Nat \to Proof                       (* projection         *)
+   | prin: Nat \to Proof                       (* pos rel inhabitant *)
+   | impw: Proof \to Proof                     (* weakening          *)
+   | impr: Proof \to Proof                     (* right introduction *)
+   | impi: Proof \to Proof \to Proof \to Proof (* left introduction  *)
+   | scut: Proof \to Proof \to Proof           (* symmetric cut      *)
+.