A body of authoritative officials organized in nested ranks.

plural of hierarchy

Alternative form of hierarchical

(logic) arithmetical hierarchy

(logic) A hierarchy which classifies the complexity of first-order formulae (and sets defined by them) based on the number of alternations between series of unbounded existential quantifiers and universal quantifiers.

(computer science, linguistics) A containment hierarchy of classes of formal grammars. From least to most specialized, the classes are: recursively enumerable, context-sensitive, context-free, and regular.

(marketing) Any of various hierarchical models according to which customers progress through a series of stages, from first becoming aware of a brand through to making a purchase.

plural of Chomsky hierarchy

plural of arithmetic hierarchy

plural of arithmetical hierarchy