Give an example of a relation. Which is
Symmetric but neither reflexive nor transitive.
Let A = {3,4,5}
Define a relation R on A as R = {(3,4), (4,3)}
Relation R is not reflexive as (3,3), (4,4) and (5,5) ∉ R.
Now, as (3,4) ϵ R and also (4,3) ϵ R,
R is symmetric.
⇒ (3,4), (4,3) ϵ R, but (3,3) ∉ R
⇒ R is not transitive.
Therefore, relation R is symmetric but not reflexive or transitive.