The dot in the region of intersection shows that at least one mortal is a cat. The diagram does not
show the “people” and “cats” circle intersecting with a dot in the region of intersection.
The argument is valid if and only if every possible diagram illustrates the conclusion of the
argument. The argument’s conclusion is: Some people are cats. The diagram does not show the
“people” circle and the “cats” circle intersecting with a dot in the region of intersection. The
conclusion does not follow from the premises. The argument is invalid.