(* BASIC LOCAL ENVIRONMENT THINNING *****************************************)
definition thin: nat → nat → relation lenv ≝
(* BASIC LOCAL ENVIRONMENT THINNING *****************************************)
definition thin: nat → nat → relation lenv ≝
- λd,e,L1,L2. ∃∃L. L1 ▶* [d, e] L & ⇩[d, e] L ≡ L2.
+ λd,e,L1,L2. â\88\83â\88\83L. L1 â\8a¢ â\96¶* [d, e] L & â\87©[d, e] L â\89¡ L2.
lemma thin_inv_thin1: ∀I,K1,V1,L2,e. ▼*[0, e] K1.ⓑ{I} V1 ≡ L2 → 0 < e →
▼*[0, e - 1] K1 ≡ L2.
#I #K1 #V1 #L2 #e * #X #HK1 #HL2 #e
lemma thin_inv_thin1: ∀I,K1,V1,L2,e. ▼*[0, e] K1.ⓑ{I} V1 ≡ L2 → 0 < e →
▼*[0, e - 1] K1 ≡ L2.
#I #K1 #V1 #L2 #e * #X #HK1 #HL2 #e