anchor.diff:        $result =
            ($bl_formula.result).forSome
            (
  -            next_node.in
  +            next_node.oneOf
               (
                  current_node.join
                  (
  
positive.code:             Main.get_variable_manager().get_variable
              (
                 ($var.text)
              ).in
              (
                 Main.get_model().get_type_as_relation(($type.text))
              )
  
negative.code:       $result =
           ($f1.result).forAll
           (
              f1_node.oneOf
              (
                 f2_node.join
                 (
  