Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Determine the number of different equivalence relations on a set with four elements by listing them.

Short Answer

Expert verified

There are \(15\) distinct equivalence relations on \(S\), as listed below.

Step by step solution

Achieve better grades quicker with Premium

  • Unlimited AI interaction
  • Study offline
  • Say goodbye to ads
  • Export flashcards

Over 22 million students worldwide already upgrade their learning with Vaia!

01

Given data

Let the four element set \(S = \{ a,b,c,d\} \).

02

Concept  used of Equivalence relation

An equivalence relation is a binary relation that is reflexive, symmetric and transitive.

03

Find the equivalence relations

The required number of equivalence relations on \(S\) is just the number of ways of partitioning the set \(S\).

They fall into following types:

\(\{ (a),(b),(c),(d)\} \)(Singletons), number of such partitions is \(1\).

\(\{ (a),\{ b,c,d\} \} \)(One singleton, one triple) number of such partitions is \(4\).

\(\{ (a,b),(c,d)\} \)(two disjoint pairs\} number of such partitions is \(6\).

\(\{ (a,b),(c),(d)\} \)(One doubleton, two singletons) number of partitions is \(3\).

\(\{ a,b,c,d\} \)(No proper partition) number of partition is \(1\).

Total number of equivalence classes is the total number or partitions \( = 15\).

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.

Sign-up for free