(* Advanced properties ******************************************************)
(* Note: lemma 250 *)
+(* Basic_2A1: uses: lpr_refl *)
lemma lfpr_refl: ∀h,G,T. reflexive … (lfpr h G T).
/2 width=1 by lfxs_refl/ qed.
-lemma lfpr_pair: ∀h,G,L,V1,V2. ⦃G, L⦄ ⊢ V1 ➡[h] V2 →
- ∀I,T. ⦃G, L.ⓑ{I}V1⦄ ⊢ ➡[h, T] L.ⓑ{I}V2.
-/2 width=1 by lfxs_pair/ qed.
+(* Basic_2A1: uses: lpr_pair *)
+lemma lfpr_pair_refl: ∀h,G,L,V1,V2. ⦃G, L⦄ ⊢ V1 ➡[h] V2 →
+ ∀I,T. ⦃G, L.ⓑ{I}V1⦄ ⊢ ➡[h, T] L.ⓑ{I}V2.
+/2 width=1 by lfxs_pair_refl/ qed.
+
+(* Advanced inversion lemmas ************************************************)
+
+lemma lfpr_inv_bind_void: ∀h,p,I,G,L1,L2,V,T. ⦃G, L1⦄ ⊢ ➡[h, ⓑ{p,I}V.T] L2 →
+ ∧∧ ⦃G, L1⦄ ⊢ ➡[h, V] L2 & ⦃G, L1.ⓧ⦄ ⊢ ➡[h, T] L2.ⓧ.
+/2 width=3 by lfxs_inv_bind_void/ qed-.
+
+(* Advanced forward lemmas **************************************************)
+
+lemma lfpr_fwd_bind_dx_void: ∀h,p,I,G,L1,L2,V,T.
+ ⦃G, L1⦄ ⊢ ➡[h, ⓑ{p,I}V.T] L2 → ⦃G, L1.ⓧ⦄ ⊢ ➡[h, T] L2.ⓧ.
+/2 width=4 by lfxs_fwd_bind_dx_void/ qed-.