It was ruled by King Tethra, a Fomorian or Manannan mac Lir. Queen Niamh ruled Tir na n-Og.
See also: Aericura, Aillen
... our quadratic equation by a, we have <math> x^2 + \left( \frac{b}{a} \right) x + \frac{c}{a}=0 </math> which is equivalen ...