Understanding symmetric and antisymmetric relations

Question

I'm having an issue working out if the following is just antisymmetric or antisymmetric and symmetric

$\{(1,1),(2,2),(3,3)\}$

I'm certain its antisymmetric but im just not certain if the rule

$R$ is symmetric if whenever $(a, b)\in R$ then $(b, a) \in R$.

applies when $a=b$. Thanks for any help.

Thanks I presumed so but I was doubting myself to had to check! — Mark, Jan 18 '17 at 18:31

Kanwaljit Singh · Accepted Answer · 2017-01-18 18:30:22Z

0

Symmetric means if $(1,2) \in R$, then $(2,1) \in R$. In your example, all elements are of the form $(1,1)$ so it is true.

answered Jan 18 '17 at 18:30

Kanwaljit Singh

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$\begingroup$ Thanks I presumed so but was doubting myself so had to check! $\endgroup$ – Mark Jan 18 '17 at 18:31
$\begingroup$ Your welcome. Hope your doubt now clear. $\endgroup$ – Kanwaljit Singh Jan 18 '17 at 18:31

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