(* Main properties **********************************************************)
-theorem gdrop_mono: â\88\80G,G1,e. â\87\93[e] G â\89¡ G1 â\86\92 â\88\80G2. â\87\93[e] G ≡ G2 → G1 = G2.
+theorem gdrop_mono: â\88\80G,G1,e. â\87©[e] G â\89¡ G1 â\86\92 â\88\80G2. â\87©[e] G ≡ G2 → G1 = G2.
#G #G1 #e #H elim H -G -G1
[ #G #He #G2 #H
>(gdrop_inv_gt … H He) -H -He //
]
qed-.
-lemma gdrop_dec: â\88\80G1,G2,e. Decidable (â\87\93[e] G1 ≡ G2).
+lemma gdrop_dec: â\88\80G1,G2,e. Decidable (â\87©[e] G1 ≡ G2).
#G1 #G2 #e
elim (gdrop_total e G1) #G #HG1
elim (genv_eq_dec G G2) #HG2