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 "basic_2/substitution/ldrops_ldrop.ma".
17 (* ITERATED LOCAL ENVIRONMENT SLICING ***************************************)
19 (* Main properties **********************************************************)
21 (* Basic_1: was: drop1_trans *)
22 theorem ldrops_trans: ∀L,L2,s,des2. ⇩*[s, des2] L ≡ L2 → ∀L1,des1. ⇩*[s, des1] L1 ≡ L →
23 ⇩*[s, des2 @@ des1] L1 ≡ L2.
24 #L #L2 #s #des2 #H elim H -L -L2 -des2 /3 width=3 by ldrops_cons/