Sextus Empiricus Pyrrhoniae Hypotyposes 2.13.147

[147] And it is a case of redundancy when we find a premiss that is superfluous for the logic of the argument, as for instance ‟If it is day, it is light; but in fact it is day and Dion also is walking; therefore it is light.” And it is due to the bad form in which it is propounded when the form of the argument is not conclusive; for whereas the really syllogistic arguments are, they say, such as these: ‟If it is day, it is light; but in fact it is day; therefore it is light;” and ‟If it is day, it is light; but it is not light; therefore it is not day,”—the inconclusive argument runs thus: ‟If it is day, it is light; but in fact it is light; therefore it is day.”