anchor.diff:        $result =
            ($bl_formula.result).forSome
            (
  -            next_node.in
  +            next_node.oneOf
               (
                  chosen_path.join
                  (
  
positive.code:       $result =
           ($bl_formula.result).forSome
           (
              next_node.in
              (
                 chosen_path.join
                 (
  
negative.code:             Main.get_variable_manager().get_variable
              (
                 ($var.text)
              ).oneOf
              (
                 Main.get_model().get_type_as_relation(($type.text))
              )
  