A Relation R : A → A → \Omegal : 𝑅 → 𝐴 𝐴 → \Omegal R:A\to A\to\Omegal is antireflexive if for all x : A : 𝑥 𝐴 x:A , ¬ R ( x , x ) 𝑅 𝑥 𝑥 \lnot R(x,x) .