Buchholz - Wikipedia
https://en.wikipedia.org/wiki/Buchholz
WebBuchholz (surname) Buchholz hydra, a mathematical game on a labeled tree. Buchholz psi functions, a system of ordinal collapsing functions. Buchholz's ID hierarchy, a hierarchy of inductively defined mathematical systems. Buchholz relay, a safety device for oil-filled electrical transformers. Buchholz system, a chess ranking system.
DA: 71 PA: 66 MOZ Rank: 86