premise: To prepare for fieldwork, exactly four different researchers—a geologist, a historian, a linguist, and a paleontologist—will learn at least one and at most three of four languages—Rundi, Swahili, Tigrinya, and Yoruba. They must learn the languages according to the following specifications: Exactly one researcher learns Rundi. Exactly two researchers learn Swahili. Exactly two researchers learn Tigrinya. Exactly three researchers learn Yoruba. Any language learned by the linguist or paleontologist is not learned by the geologist. Any language learned by the geologist is learned by the historian. Which one of the following must be true?
hypothesis: Fewer of the languages are learned by the geologist than are learned by the historian.