Concept · Foundations

Relation

A binary relation from A to B is a subset R ⊆ A × B; elements (a, b) ∈ R are usually written a R b.

Why it matters

Every kind of structure in mathematics — order, equivalence, function, graph — is ultimately a relation, and treating relations as sets of ordered pairs gives them rigorous definitions.

Where this shows up

Units and lessons using this concept

Following the links will take you to the page where this term is introduced in context.

Units (1)

Set Theory and Relations: The Structure Underneath LogicStudents learn the language of sets, relations, and functions that underlies most of modern formal logic. They master set operations, rel…

Lessons (3)

Capstone: Using Set Theory in Logic and ArgumentSet Theory and Relations: The Structure Underneath Logic Functions and CardinalitySet Theory and Relations: The Structure Underneath Logic Relations and Their PropertiesSet Theory and Relations: The Structure Underneath Logic

Other concepts in Foundations

A, E, I, O Propositions Accessibility Relation Argument Atomic Statement Authorial Intent Base Rate Bayes Factor Burden of Proof in Interpretation Calibration Cardinality Cartesian Product Categorical Proposition