+
+lemma cnv_fwd_cpms_abst_dx_le (h) (a) (G) (L) (W) (p):
+ ∀T. ❨G,L❩ ⊢ T ![h,a] →
+ ∀n1,U1. ❨G,L❩ ⊢ T ➡*[h,n1] ⓛ[p]W.U1 → ∀n2. n1 ≤ n2 →
+ ∃∃U2. ❨G,L❩ ⊢ T ➡*[h,n2] ⓛ[p]W.U2 & ❨G,L.ⓛW❩ ⊢ U1 ➡*[h,n2-n1] U2.
+#h #a #G #L #W #p #T #H
+elim (cnv_fwd_aaa … H) -H #A #HA
+/2 width=2 by cpms_abst_dx_le_aaa/
+qed-.
+
+(* Advanced properties ******************************************************)
+
+lemma cnv_appl_ge (h) (a) (n1) (p) (G) (L):
+ ∀n2. n1 ≤ n2 → ad a n2 →
+ ∀V. ❨G,L❩ ⊢ V ![h,a] → ∀T. ❨G,L❩ ⊢ T ![h,a] →
+ ∀X. ❨G,L❩ ⊢ V ➡*[h,1] X → ∀W. ❨G,L❩ ⊢ W ➡*[h,0] X →
+ ∀U. ❨G,L❩ ⊢ T ➡*[h,n1] ⓛ[p]W.U → ❨G,L❩ ⊢ ⓐV.T ![h,a].
+#h #a #n1 #p #G #L #n2 #Hn12 #Ha #V #HV #T #HT #X #HVX #W #HW #X #HTX
+elim (cnv_fwd_cpms_abst_dx_le … HT … HTX … Hn12) #U #HTU #_ -n1
+/4 width=11 by cnv_appl, cpms_bind, cpms_cprs_trans/
+qed.