(* Advanced inversion lemmas ************************************************)
lemma cnx_inv_abbr_pos (G) (L):
(* Advanced inversion lemmas ************************************************)
lemma cnx_inv_abbr_pos (G) (L):
#G #L #V #U1 #H
elim (cpx_subst G (L.ⓓV) U1 … 0) [|*: /2 width=4 by drops_refl/ ] #U2 #T2 #HU12 #HTU2
elim (teqx_dec U1 U2) #HnU12 [ -HU12 | -HTU2 ]
#G #L #V #U1 #H
elim (cpx_subst G (L.ⓓV) U1 … 0) [|*: /2 width=4 by drops_refl/ ] #U2 #T2 #HU12 #HTU2
elim (teqx_dec U1 U2) #HnU12 [ -HU12 | -HTU2 ]