Definition:Equivalence Relation Induced by Mapping
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Definition
Let $f: S \to T$ be a mapping.
Let $\RR_f \subseteq S \times S$ be the relation defined as:
- $\tuple {s_1, s_2} \in \RR_f \iff \map f {s_1} = \map f {s_2}$
Then $\RR_f$ is known as the equivalence (relation) induced by $f$.
Also known as
The equivalence induced by $f$ is variously known as:
- the (equivalence) relation (on $S$) induced by (the mapping) $f$
- the (equivalence) relation (on $S$) defined by (the mapping) $f$
- the (equivalence) relation (on $S$) associated with (the mapping) $f$
- the equivalence kernel of $f$.
Also see
- Relation Induced by Mapping is Equivalence Relation for a demonstration that $\RR_f$ is indeed an equivalence relation.
Sources
- 1951: Nathan Jacobson: Lectures in Abstract Algebra: Volume $\text { I }$: Basic Concepts ... (previous) ... (next): Introduction $\S 3$: Equivalence relations
- 1960: Paul R. Halmos: Naive Set Theory ... (previous) ... (next): $\S 8$: Functions
- 1965: Seth Warner: Modern Algebra ... (previous) ... (next): Chapter $\text {II}$: New Structures from Old: $\S 10$: Equivalence Relations
- 1967: George McCarty: Topology: An Introduction with Application to Topological Groups ... (previous) ... (next): Chapter $\text{I}$: Sets and Functions: Factoring Functions: Theorem $10$
- 1968: A.N. Kolmogorov and S.V. Fomin: Introductory Real Analysis ... (previous) ... (next): $\S 1.4$: Decomposition of a set into classes. Equivalence relations: Example $1$
- 1972: A.G. Howson: A Handbook of Terms used in Algebra and Analysis ... (previous) ... (next): $\S 3$: Equivalence relations and quotient sets: Quotient sets
- 1975: T.S. Blyth: Set Theory and Abstract Algebra ... (previous) ... (next): $\S 6$. Indexed families; partitions; equivalence relations: Example $6.6$
- 1982: P.M. Cohn: Algebra Volume 1 (2nd ed.) ... (previous) ... (next): Chapter $1$: Sets and mappings: $\S 1.4$: Equivalence relations
- 2000: James R. Munkres: Topology (2nd ed.) ... (previous) ... (next): $1$: Set Theory and Logic: $\S 3$: Relations: Exercise $3.4$