In this task, you will be presented with a context passage, a question about that paragraph, and a possible answer to that question. The task is to check the validity of the answer. Answer with "Yes" or "No".

Example Input: As for engravings, Durer's work was restricted to portraits and illustrations for his treatise. The portraits include Cardinal-Elector Albert of Mainz; Frederick the Wise, elector of Saxony; the humanist scholar Willibald Pirckheimer; Philipp Melanchthon, and Erasmus of Rotterdam. For those of the Cardinal, Melanchthon, and Durer's final major work, a drawn portrait of the Nuremberg patrician Ulrich Starck, Durer depicted the sitters in profile, perhaps reflecting a more mathematical approach. Despite complaining of his lack of a formal classical education, Durer was greatly interested in intellectual matters and learned much from his boyhood friend Willibald Pirckheimer, whom he no doubt consulted on the content of many of his images. He also derived great satisfaction from his friendships and correspondence with Erasmus and other scholars. Durer succeeded in producing two books during his lifetime. "The Four Books on Measurement" were published at Nuremberg in 1525 and was the first book for adults on mathematics in German, as well as being cited later by Galileo and Kepler. The other, a work on city fortifications, was published in 1527. "The Four Books on Human Proportion" were published posthumously, shortly after his death in 1528. <sep>Whom did Durer both draw a porter of and consult with?<sep>Willibald Pirckheimer
Example Output: Yes

Example Input: The inhabited history of the Las Vegas Valley stretches to 23,000 b.c. , when much of the area was covered by a prehistoric lake. During this period, the indigenous people lived in caves, hunting the mammals that gathered at the shoreline. The landscape of the valley changed dramatically over the next 200 centuries. The glaciers feeding the lake melted away and the lake evaporated. Fossils tell an obscure story of man's slow and sporadic development. Around 3000 b.c. , native Archaic Indians began to develop a lasting hunting and gathering culture. By this time, the valley was in much the same geographic state as it exists in today, with one exception — the presence of artesian springs that bubbled to the surface in several areas. These springs fed a network of streams draining through the Las Vegas Wash to the Colorado River. The areas surrounding the springs were desert oases: sprawling collections of grasses, trees, and wildlife. Many springs lay in areas that would eventually become the center of the modern Las Vegas metropolis. For about 4000 years, the Archaics thrived in a culture that included many signs of early civilization. Signs of even more advancement appeared halfway through the first millennium a.d. , when the Anasazi Indians inhabited the valley. Far more progressive than the Archaics, the Anasazi utilized such formal agricultural techniques as irrigation to assist their harvest. This permitted the Anasazi to achieve a benchmark of advanced society — the ability to live in permanent shelters year-round without need to follow wildlife. Mysteriously, the Anasazi vanished from the valley around a.d. <sep>Why did the prehistoric lake disappear from the Las Vegas Valley?<sep>Deforestation
Example Output: No

Example Input: Alexander married twice: Roxana, daughter of the Bactrian nobleman Oxyartes, out of love; and Stateira II, a Persian princess and daughter of Darius III of Persia, for political reasons. He apparently had two sons, Alexander IV of Macedon of Roxana and, possibly, Heracles of Macedon from his mistress Barsine. He lost another child when Roxana miscarried at Babylon. Alexander also had a close relationship with his friend, general, and bodyguard Hephaestion, the son of a Macedonian noble. Hephaestion's death devastated Alexander. This event may have contributed to Alexander's failing health and detached mental state during his final months. Alexander's sexuality has been the subject of speculation and controversy. No ancient sources stated that Alexander had homosexual relationships, or that Alexander's relationship with Hephaestion was sexual. Aelian, however, writes of Alexander's visit to Troy where "Alexander garlanded the tomb of Achilles and Hephaestion that of Patroclus, the latter riddling that he was a beloved of Alexander, in just the same way as Patroclus was of Achilles". Noting that the word eromenos (ancient Greek for beloved) does not necessarily bear sexual meaning, Alexander may have been bisexual, which in his time was not controversial. Green argues that there is little evidence in ancient sources that Alexander had much carnal interest in women; he did not produce an heir until the very end of his life. However, he was relatively young when he died, and Ogden suggests that Alexander's matrimonial record is more impressive than his father's at the same age. Apart from wives, Alexander had many more female companions. Alexander accumulated a harem in the style of Persian kings, but he used it rather sparingly; showing great self-control in "pleasures of the body". Nevertheless, Plutarch described how Alexander was infatuated by Roxana while complimenting him on not forcing himself on her. Green suggested that, in the context of the period, Alexander formed quite strong friendships with women, including Ada of Caria, who adopted him, and even Darius's mother Sisygambis, who supposedly died from grief upon hearing of Alexander's death. <sep>Did any ancient sources confirm that Alexander had a sexual relationship with his bodyguard?<sep>Alexander also had a close relationship with his friend, general, and bodyguard Hephaestion, the son of a Macedonian noble
Example Output:
No

