Planning Areas of Singapore increasingly adopted these boundaries for their administrative purposes. For example, the Statistics Department of Singapore published its 2000 census data based on planning area boundaries for the first time, compared to using census divisions based on electoral boundaries for previous exercises. The Singapore Police Force's (SPF) neighbourhood police centres have jurisdiction boundaries based on planning area boundaries when they were officially gazetted in 1999, as opposed to electoral divisions under the previous neighbourhood Police Post system. Planning Areas are further subdivided into subzones for statistical purposes. <nowiki>*</nowiki> = Place names attested to be of Malay origin and referred to similarly
Subdivided interval categories Subdivided interval categories In category theory (mathematics) there exists an important collection of categories denoted formula_1 for natural numbers formula_2. The objects of formula_3 are the integers formula_4, and the morphism set formula_5 for objects formula_6 is empty if formula_7. Subdivided interval categories are very useful in defining simplicial sets. The category whose objects are the subdivided interval categories and whose morphisms are functors is often written formula_8 and is called the simplicial indexing category. A simplicial set is just a contravariant functor formula_9. The category 𝟘 is an empty interval, that is, an empty category, having no objects nor