hierarchy
131Difference hierarchy — In set theory, the difference hierarchy over a pointclass is a hierarchy of larger pointclasses generated by taking differences of sets. If Γ is a pointclass, then the set of differences in Γ is . In usual notation, this set is denoted by 2 Γ.… …
132Case hierarchy — In linguistic typology, the case hierarchy states grammatical cases in order of their prominence. It should therefore be concluded that a language which makes use of any given case will also make use of all the cases which are higher (further… …
