]> matita.cs.unibo.it Git - helm.git/blobdiff - matita/matita/contribs/lambdadelta/basic_2/unfold/tpss.ma
- lambdadelta: first recursive part of preservation finally proved!
[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / unfold / tpss.ma
index 93916208b649a6d301c53ab4ef1e56f9d6417871..faafb36d16c422160bdb680be2736d2f7d3f872f 100644 (file)
@@ -40,6 +40,9 @@ qed-.
 
 (* Basic properties *********************************************************)
 
+lemma tps_tpss: ∀L,T1,T2,d,e. L ⊢ T1 ▶ [d, e] T2 → L ⊢ T1 ▶* [d, e] T2.
+/2 width=1/ qed.
+
 lemma tpss_strap1: ∀L,T1,T,T2,d,e.
                    L ⊢ T1 ▶* [d, e] T → L ⊢ T ▶ [d, e] T2 → L ⊢ T1 ▶* [d, e] T2. 
 /2 width=3/ qed.
@@ -164,7 +167,7 @@ qed-.
 
 (* Basic forward lemmas *****************************************************)
 
-lemma tpss_fwd_tw: ∀L,T1,T2,d,e. L ⊢ T1 ▶* [d, e] T2 → #{T1} ≤ #{T2}.
+lemma tpss_fwd_tw: ∀L,T1,T2,d,e. L ⊢ T1 ▶* [d, e] T2 → ♯{T1} ≤ ♯{T2}.
 #L #T1 #T2 #d #e #H @(tpss_ind … H) -T2 //
 #T #T2 #_ #HT2 #IHT1
 lapply (tps_fwd_tw … HT2) -HT2 #HT2