The use of Venn diagrams was first formalized by English philosopher and mathematician John Venn, who wrote a paper in 1880 entitled "On the Diagrammatic and Mechanical Representation of ...

Typical two- and three-circle Venn diagrams share this property. Rotate a two-circle Venn diagram by 180 degrees (or a three-circle one by 120 degrees), and it looks the same. But the four-ellipse ...

So, diagram the A/B premise and the B/C premise onto the three circles. If what comes out when we look at the A/C circles entails the representation of the form of the conclusion, BOOM, the ...