fornication

n 1: voluntary sexual intercourse between persons not married to

each other

2: extramarital sex that willfully and maliciously interferes

with marriage relations; "adultery is often cited as

grounds for divorce" [syn: {adultery}, {criminal

conversation}]

foundation

The axiom of foundation states that the membership relation is

well founded, i.e. that any non-empty collection Y of sets has

a member y which is disjoint from Y. This rules out sets

which contain themselves (directly or indirectly).