Just as a pedantic aside, people often use Venn diagram when they mean Euler diagram. A Venn diagram always has the overlapping circles and use shading or labeling describe the set relation. Euler diagrams let the circles describe the relation so two non intersecting sets in a Venn diagram might share the left circle green, the right blue and leave the intersection blank or grey. An Euler diagram will have two disjoint circles.

A. I love a pedantic aside

B. I love that Euler is pronounced “oiler” which is North American slang for a drunk. I’ve been trying to find that constant my whole adult life.

I learned the correct pronunciation when someone laughed at me at a TeX conference in the 80s when I made a reference to the You-ler fonts. In my single semester of high school German I was either never taught or ignored the teacher when the pronunciation of eu was given (or perhaps I just never connected it with Euler).