Your task is to learn a class of objects by example. Without seeing any negative examples, you're unlikely to learn the right class (which is unique, it is prec

Your task is to learn a class of objects by example. Without seeing any negative examples, you're unlikely to learn the right class (which is unique, it is precisely the class of increasing sequences of length 3). (x, 2x, 4x) is not "a correct answer", as it does not describe the class you were supposed to learn to distinguish.