| Appl of term list
| Binder of binder_kind * capture_variable * term
| Case of term * string option * term option * (case_pattern * term) list
+ | Cast of term * term
| LetIn of capture_variable * term * term
| LetRec of induction_kind * (capture_variable * term * int) list * term
| Ident of string * subst list option