Quandle

English

Etymology

Coined by David Joyce in his 1982 paper A classifying invariant of knots: the knot quandle.

Noun

1. Template:Lb A rack, $\mathrm{Q}$, such that $\mathrm{\forall }a\in \mathrm{Q}$ $a▹a=a$ or equivalently $a◃a=a$.