In philosophy, specifically metaphysics, mereology is the study of parthood relationships. In mathematics and formal logic, wellfoundedness prohibits for any x.
Thus non-wellfounded mereology treats topologically circular, cyclical, repetitive, or other eventual self-containment.
More formally, non-wellfounded partial orders may exhibit for some x whereas well-founded orders prohibit that.
See also
Aczel's anti-foundation axiom Peter Aczel John Barwise Steve Awodey Dana Scott
External links