inductive gdrop (e:nat): relation genv ≝
| gdrop_gt: ∀G. |G| ≤ e → gdrop e G (⋆)
| gdrop_eq: ∀G. |G| = e + 1 → gdrop e G G
-| gdrop_lt: ∀I,G1,G2,V. e < |G1| → gdrop e G1 G2 → gdrop e (G1. 𝕓{I} V) G2
+| gdrop_lt: ∀I,G1,G2,V. e < |G1| → gdrop e G1 G2 → gdrop e (G1. ⓑ{I} V) G2
.
interpretation "global slicing"
]
qed-.
-fact gdrop_inv_lt_aux: ∀I,G,G1,G2,V,e. ⇩[e] G ≡ G2 → G = G1. 𝕓{I} V →
+fact gdrop_inv_lt_aux: ∀I,G,G1,G2,V,e. ⇩[e] G ≡ G2 → G = G1. ⓑ{I} V →
e < |G1| → ⇩[e] G1 ≡ G2.
#I #G #G1 #G2 #V #e * -G -G2
[ #G #H1 #H destruct #H2
qed.
lemma gdrop_inv_lt: ∀I,G1,G2,V,e.
- ⇩[e] G1. 𝕓{I} V ≡ G2 → e < |G1| → ⇩[e] G1 ≡ G2.
+ ⇩[e] G1. ⓑ{I} V ≡ G2 → e < |G1| → ⇩[e] G1 ≡ G2.
/2 width=5/ qed-.
(* Basic properties *********************************************************)