# What is the closure of a relation?

## What is the closure of a relation?

Definition: The closure of a relation R with respect to property P is the relation obtained by adding the minimum number of ordered pairs to R to obtain property P. In terms of the digraph representation of R • To find the reflexive closure – add loops.

What is symmetric closure of a relation?

The symmetric closure of a relation R on a set A is defined as the smallest symmetric relation s(R) on A that contains R. The symmetric closure s(R) is obtained by adding the elements (b,a) to the relation R for each pair (a,b)∈R.

What is reflexive closure example?

In mathematics, the reflexive closure of a binary relation R on a set X is the smallest reflexive relation on X that contains R. For example, if X is a set of distinct numbers and x R y means “x is less than y”, then the reflexive closure of R is the relation “x is less than or equal to y”.

### How do you do reflexive closures?

Reflexive Closure The reflexive closure of a relation R on A is obtained by adding (a, a) to R for each a ∈ A. Symmetric Closure The symmetric closure of R is obtained by adding (b, a) to R for each (a, b) ∈ R. The transitive closure of R is obtained by repeatedly adding (a, c) to R for each (a, b) ∈ R and (b, c) ∈ R.

How to obtain the closure of a relation?

(1) Reflexive and Symmetric Closures: The next theorem tells us how to obtain the reflexive and symmetric closures of a relation easily. Theorem: Let R be a relation on a set A. Then: R ∪ R -1 is the symmetric closure of R.

Which is the P closure of a relation?

The P-closure of an arbitrary relation R on A, indicated P (R), is a P-relation such that (1) Reflexive and Symmetric Closures: The next theorem tells us how to obtain the reflexive and symmetric closures of a relation easily. Theorem: Let R be a relation on a set A. Then: Let A = {k, l, m}. Let R is a relation on A defined by

#### Which is more complex the transitive closure or the reflexive closure?

Transitive Closure The transitive closure of a binary relation R on a set A is the smallest transitive relation t(R) on A containing R. The transitive closure is more complex than the reflexive or symmetric closures.

Which is a binary relation over a set?

Binary Relations ●Intuitively speaking: a binary relation over a set Ais some relation Rwhere, for every x, y∈ A, the statement xRyis either true or false. ●Examples: ●< can be a binary relation over ℕ, ℤ, ℝ, etc. ●↔ can be a binary relation over Vfor any undirected graph G= (V, E). ●≡ₖis a binary relation over ℤ for any integer k.