NaΓ―ve set theory MOC Relation A relation between sets π΄ and π΅ is a construct which relates elements π βπ΄ or π βπ΅, so that π βΌπ is either true or false. set We may therefore define a relation π as the following subset of the cartesian product π΄ Γπ΅ π ={(π,π)βπ΄Γπ΅:πβΌπ} or equivalently as a function π΄ Γπ΅ βΞ©. A special class of relation is the Equivalence relation. See also Relation class. tidy | SemBr | en