-#n #h #p #G #L #V1 #T1 #U2 * #c #Hc #H elim (cpg_inv_abst1 … H) -H
-#cV #cT #V2 #T2 #HV12 #HT12 #H1 #H2 destruct
-elim (isrt_inv_max … Hc) -Hc #nV #nT #HcV #HcT #H destruct
-elim (isrt_inv_shift … HcV) -HcV #HcV #H destruct
-/3 width=5 by ex3_2_intro, ex2_intro/
+#n #h #p #G #L #V1 #T1 #U2 #H
+elim (cpm_inv_bind1 … H) -H
+[ /3 width=1 by or_introl/
+| * #T #_ #_ #_ #H destruct
+]
+qed-.
+
+lemma cpm_inv_abst_bi: ∀n,h,p1,p2,G,L,V1,V2,T1,T2. ⦃G,L⦄ ⊢ ⓛ{p1}V1.T1 ➡[n,h] ⓛ{p2}V2.T2 →
+ ∧∧ ⦃G,L⦄ ⊢ V1 ➡[h] V2 & ⦃G,L.ⓛV1⦄ ⊢ T1 ➡[n,h] T2 & p1 = p2.
+#n #h #p1 #p2 #G #L #V1 #V2 #T1 #T2 #H
+elim (cpm_inv_abst1 … H) -H #XV #XT #HV #HT #H destruct
+/2 width=1 by and3_intro/