model relation1 {

  var x, y;

  states start, lbl_4_1, stop;

  transition t_22 := {
    from   := start;
    to     := lbl_4_1;
    guard  := true;
    action := x' = ?;
  };

  transition t_18 := {
    from   := lbl_4_1;
    to     := stop;
    guard  := true;
    action := y' = x;
  };

}

strategy relation1_s {

  Region init := {state = start};

}