With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: History of art includes Sculpture.
text_B: Frederick , Duke of Opava -LRB- Bedrich Opavsky Friedrich von Troppau -- 1470 -RRB- was a member of the Opava branch of the Bohemian Premyslid dynasty .. Premyslid dynasty. Premyslid dynasty. Opava. Duchy of Opava. He was co-ruler of Opava from 1452 to 1456 .. Opava. Duchy of Opava
not_related.