Let A = {a, b, c} and the relation R be defined on A as follows R={(a,a), (b, c), (a, b)}. Then, write a minimum number of ordered pairs to be added in R to make it reflexive and transitive.
Recall that,
R is symmetric if for all x, y ∈ A, if xRy, then yRx.
R is transitive if for all x, y, z ∈ A, if xRy and yRz, then xRz.
We have relation R = {(a, a), (b, c), (a, b)} on A.
A = {a, b, c}
For Transitive:
If (a, b) ∈ R and (b, c) ∈ R
Then, (a, c) ∈ R
∀ a, b, c ∈ A
For Reflexive:
∀ a, b, c ∈ R
Then, (a, a) ∈ R
(b, b) ∈ R
(c, c) ∈ R
We need to add (b, b), (c, c) and (a, c) in R.
We get
R = {(a, a), (b, b), (c, c), (a, b), (b, c), (a, c)}