premise: Seven students—fourth-year students Kim and Lee; third-year students Pat and Robin; and second-year students Sandy, Terry, and Val—and only those seven, are being assigned to rooms of equal size in a dormitory. Each room assigned must have either one, or two, or three students assigned to it, and will accordingly be called either a single, or a double, or a triple. The seven students are assigned to rooms in accordance with the following conditions: No fourth-year student can be assigned to a triple. No second-year student can be assigned to a single. Lee and Robin must not share the same room. Kim and Pat must share the same room. If Robin is assigned to a triple, which one of the following must be true?
hypothesis: None of the rooms assigned to the students is a single.