From: Ferruccio Guidi Date: Sat, 14 May 2011 18:59:20 +0000 (+0000) Subject: we added a property X-Git-Tag: make_still_working~2517 X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=2a33a51a4749ca91dfaa488b9c0d2a286265cf99;p=helm.git we added a property --- diff --git a/matita/matita/lib/lambda-delta/substitution/thin.ma b/matita/matita/lib/lambda-delta/substitution/thin.ma index dd3d0ffa9..00e52947d 100644 --- a/matita/matita/lib/lambda-delta/substitution/thin.ma +++ b/matita/matita/lib/lambda-delta/substitution/thin.ma @@ -23,3 +23,13 @@ inductive thin: lenv → nat → nat → lenv → Prop ≝ . interpretation "thinning" 'RSubst L1 d e L2 = (thin L1 d e L2). + +(* the main properties ******************************************************) + +axiom thin_conf_ge: ∀d1,e1,L,L1. ↓[d1,e1] L ≡ L1 → + ∀e2,L2. ↓[0,e2] L ≡ L2 → d1 + e1 ≤ e2 → ↓[0,e2-e1] L1 ≡ L2. + +axiom thin_conf_lt: ∀d1,e1,L,L1. ↓[d1,e1] L ≡ L1 → + ∀e2,K2,I,V2. ↓[0,e2] L ≡ K2. ♭I V2 → + e2 < d1 → let d ≝ d1 - e2 - 1 in + ∃K1,V1. ↓[0,e2] L1 ≡ K1. ♭I V1 ∧ ↓[d,e1] K2 ≡ K1 ∧ ↑[d,e1] V1 ≡ V2.