| #V1 #V2 #T1 #T2 #_ #_ #IHV #IHT #f #X #H
elim (lifts_inv_flat1 … H) -H #W1 #U1 #HVW1 #HTU1 #H destruct
elim (IHV … HVW1) -V1 #W2 #HVW2 #HW12
- elim (IHT … HTU1) -T1 #U2 #HTU2 #HU12
+ elim (IHT … HTU1) -T1 #U2 #HTU2 #HU12
/3 width=5 by lifts_flat, tweq_cast, ex2_intro/
]
qed-.
]
qed-.
-lemma tweq_inv_abbr_pos_x_lifts_y_y (T) (f:rtmap):
+lemma tweq_inv_abbr_pos_x_lifts_y_y (T) (f):
∀V,U. +ⓓV.U ≅ T → ⇧*[f]T ≘ U → ⊥.
@(f_ind … tw) #n #IH #T #Hn #f #V #U #H1 #H2 destruct
elim (tweq_inv_abbr_pos_sn … H1) -H1 #X1 #X2 #HX2 #H destruct -V