Homework on §1.2—assigned Mon 8/30 and due Wed 9/1
Give your own example of four non-equivalent sentences that make up a “square of opposition”—i.e., two mutually exclusive sentences each of implies one of a pair of jointly exhaustive sentences and is contradictory to the other member of that pair (hint: it is enough to find a pair of mutually exclusive sentence that are not also jointly exhaustive; sentences that are contradictory to each of the two will then provide two more non-equivalent sentences for the diametrically opposite vertices of the square).
Pick one pair of sentences from your square and briefly describe a possible world in which they have different truth values.