MODULE TUnder;
(* ISO identifiers may contain underscores; the scanner must accept them
   (previously `my_var` lexed as `my` then `_var`).  Exit 42. *)
VAR
  my_var, ExitCode : INTEGER;

PROCEDURE add_two (x : INTEGER) : INTEGER;
BEGIN
  RETURN x + 2
END add_two;

BEGIN
  my_var := add_two(40);
  ExitCode := my_var
END TUnder.