Sometimes these intertwining metaphors create dramatic irony. The intertwining of the DNA strands makes long segments difficult to separate. The song contains assertive lyrics embracing her femininity and intertwining themes of sexuality and spirituality. Beginning in the 16th century, polyphony, or the intertwining of multiple melodies, arrived in Germany. Danbala and his consort Ayida Wedo are often depicted as a pair of intertwining snakes. There are a number of building societies and banks with intertwining histories. The tortoise supports a splendid carved stone stele, crowned by intertwining hornless dragons. Porticos rise gently intertwining and drawing open marbles in quatrefoils or similar figures. Her titles and the saga-like intertwining of her characters suggest high ambitions. Katz and Goldberg note the "symbolic intertwining" of the two cities. The intertwining hydrocarbon chains of sphingomyelin strengthen the myelin sheath. Such maps are also referred to as intertwining maps or morphisms. Meanwhile, Rafael also learns that Petra's pregnant as well, thus forever intertwining their lives. By doing this he is intertwining himself in the battle.