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[helm.git] / matita / contribs / RELATIONAL / NPlusList / defs.ma

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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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                  *)
+(*                                                                        *)
+(**************************************************************************)
+
+
+
+include "datatypes/List.ma".
+include "NPlus/defs.ma".
+
+
+inductive NPlusList: (List Nat) \to Nat \to Prop \def
+   | nplus_nil: NPlusList (nil ?) zero  
+   | nplus_cons: \forall l,p,q,r. 
+                 NPlusList l p \to NPlus p q r \to NPlusList (cons ? l q) r
+.
+
+definition NPlusListEq: (List Nat) \to (List Nat) \to Prop \def
+   \lambda ns1,ns2. \exists n. NPlusList ns1 n \land NPlusList ns2 n.
+
+(*
+(*CSC: the URI must disappear: there is a bug now *)
+interpretation "ternary natural plus predicate" 'rel_plus3 x y z = 
+   (cic:/matita/RELATIONAL/NPlus/defs/NPlus3.con w x y z).
+
+notation "hvbox(a break + b break + c == d)" 
+  non associative with precedence 95
+for @{ 'rel_plus3 $a $b $c $d}.
+*)