type ex =
  | E : {
      module_ :
        (module S.Analyzer
           with type Expression.t = 'a
            and type Expression.t' = 'b
            and type Instruction.t = 'c
            and type Instruction.t' = 'd
            and type Location.t = 'e
            and type context = 'f);
      expr_witness : 'a Type.Id.t;
      expr' : 'b Type.Id.t;
      instr_witness : 'c Type.Id.t;
      instr' : 'd Type.Id.t;
      location_witness : 'e Type.Id.t;
      context : 'f Type.Id.t;
    }
      -> ex  (** Type of check to apply *)

val build :
  (module S.Analyzer
     with type Expression.t = _
      and type Expression.t' = _
      and type Instruction.t = _
      and type Instruction.t' = _
      and type Location.t = 'a
      and type context = _) ->
  'a Type.Id.t * ex
(** Build a new check from a module following S.Analyzer signature. ypeid Return
    the result type which hold the final result value, and checker itself. *)