In summary — Parallel logic ↔ sets

Propositional logic and the algebra of sets are the same object, written with two different notations:

LogicSetsVenn diagram
¬p\lnot pcomplement A\overline{A}outside of the circle
pqp\land qintersection ABA\cap Boverlap
pqp\lor qunion ABA\cup Bsum of the circles
pqp\veebar qsymmetric difference ABA\triangle B“crescent-shaped”
pqp\Rightarrow qinclusion ABA\subseteq BAA entirely inside BB
VV (always true)universe UUthe whole rectangle
FF (always false)empty set \emptysetnothing

This dictionary is the key to reading the whole chapter: every logical property has a set-theoretic twin and vice versa.

Topics: Set theory
Concepts: Logical connectives · Venn diagram
People: John Venn