| C.Cast (t1, t2) -> aux (aux (offset + n) t2) t1
| C.Lambda (_, t1, t2)
| C.Prod (_, t1, t2) -> aux (aux (succ n) t2) t1
- | C.LetIn (_, t1, ty, t2) -> aux (aux (aux (offset + 1 + n) t2) ty) t1
+ | C.LetIn (_, t1, ty, t2) -> aux (aux (aux (offset + n) t2) ty) t1
| C.MutCase (_, _, t1, t2, ss) ->
aux (aux (List.fold_left aux (offset + 1 + n) ss) t2) t1
| C.Fix (_, ss) ->