1 (**************************************************************************)
4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
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15 include "ground/lib/ltc.ma".
16 include "ground/arith/nat_plus.ma".
18 (* NAT-LABELED REFLEXIVE AND TRANSITIVE CLOSURE FOR λδ-2A *******************)
20 definition lstar_aux (B) (R:relation B) (l): relation B ≝
21 λb1,b2. ∨∨ (∧∧ l = 𝟎 & b1 = b2) | (∧∧ l = 𝟏 & R b1 b2).
23 definition lstar (B) (R:relation B): nat → relation B ≝
24 ltc … nplus … (lstar_aux … R).
26 definition llstar (A) (B) (R:relation3 A B B) (l:nat): relation3 A B B ≝