type term =
  | Var of int
  | App of term * term
  | Lam of term

exception ParsingError of string

(* val problem_of_string:
 string ->
  string (* problem label *)
  * Num.i_var option (* div *)
  * Num.i_n_var list (* conv *)
  * Num.i_n_var list (* ps *)
  * string list (* names of free variables *)
val from_file : string ->
 (string (* problem label *)
 * Num.i_var option (* div *)
 * Num.i_n_var list (* conv *)
 * Num.i_n_var list (* ps *)
 * string list (* names of free variables *)) list *)

 (* parses a string to a term *)
 val parse: string -> term
 (* parse many strings/terms, and returns the list of parsed terms + the list of free variables; variable 0 is not used *)
 val parse_many: string list -> term list * string list