Use rules of inference to show whether the following arguments are valid or not: Everyone enrolled in the university has lived in a dormitory. Mia has never lived in a dormitory. Therefore, Mia is not enrolled in the university a) b) A convertible car is fun to drive. Isaac's car is not a convertible. Therefore, Isaac's car c) All lobstermen set at least a dozen traps. Hamilton is a lobsterman. Therefore, Hamilton is not fun to drive. sets at least a dozen traps