Nucleus
In order theory, a nucleus is afunction on a meet-semilattice such that (for every in):
- 1.
- 2.
- 3.
Usually, the term nucleus is used in frames and locales theory (when thesemilattice is a frame).
1 Some well known results about nuclei
Proposition If is a nucleus on a frame , then the poset of fixed points
of , with order inherited from, is also a frame.