(* activate genv *)
inductive cpy: nat → nat → relation4 genv lenv term term ≝
| cpy_atom : ∀I,G,L,d,e. cpy d e G L (⓪{I}) (⓪{I})
| cpy_subst: ∀I,G,L,K,V,W,i,d,e. d ≤ i → i < d + e →
⇩[0, i] L ≡ K.ⓑ{I}V → ⇧[0, i + 1] V ≡ W → cpy d e G L (#i) W
| cpy_bind : ∀a,I,G,L,V1,V2,T1,T2,d,e.
(* activate genv *)
inductive cpy: nat → nat → relation4 genv lenv term term ≝
| cpy_atom : ∀I,G,L,d,e. cpy d e G L (⓪{I}) (⓪{I})
| cpy_subst: ∀I,G,L,K,V,W,i,d,e. d ≤ i → i < d + e →
⇩[0, i] L ≡ K.ⓑ{I}V → ⇧[0, i + 1] V ≡ W → cpy d e G L (#i) W
| cpy_bind : ∀a,I,G,L,V1,V2,T1,T2,d,e.