S P All S's are P's. On the other hand, if we want to represent the statement that no S's are P's, besides shading the area where the S and P rectangles overlap, we also need to place an X in the area of the S rectangle that is not in the P rectangle, and in the area of the P rectangle that is not in the S rectangle. Thus. . . . S P No S's are P's. Let's see how this will work with some actual syllogisms.
All colleges are schools.
All schools are educational institutions. Some colleges are educational institutions. The easiest way to handle this is to begin by representing the premises in the same way we would if we were adopting the modern perspective. Doing this, we shade all of those areas of schools that are not educational institutions and of colleges that are not schools. Thus, we will shade the diagram as suggested below.