Venn diagram

Zelazny (working with William Blake) conjures a Venn diagram.

A Venn diagram is a machine (nonfiction) for detecting and repelling demons (nonfiction).

In addition, Venn diagrams show all possible logical relations between a finite collection of different sets; see Venn diagram (nonfiction).

Roger Zelazny

Writer/sorceror Roger Zelazny is famous for using Venn diagrams to trap demons.

He frequently then hypnotizes the demons and makes them perform embarrassing tricks in front of live audiences.

Fiction cross-reference

• John Venn
• Roger Zelazny

Nonfiction cross-reference

• Demon (nonfiction)
• John Venn (nonfiction)
• Roger Zelazny (nonfiction)
• Venn diagram (nonfiction)