Some road type classifications are influenced by city size, traffic density, and regional conventions. For example, in a very large city a primary street may have three or more lanes in each direction on a divided road. While in a town of dirt roads, the only paved single lane street could be a primary street.
subset - a set whose members are members of another set; a set contained within another set. set - (mathematics) an abstract collection of numbers or symbols; the set of prime numbers is infinite. Translations. podmnoÅ¾ina.
A subgroup is a subset H of group elements of a group G that satisfies the four group requirements. It must therefore contain the identity element. H is a subgroup of G is written H subset= G, or sometimes H<=G (e.g., Scott 1987, p. 16). The order of any subgroup of a group of order h must be a divisor of h. A subgroup H of a group G that does not include the entire group G itself is known as a proper subgroup, denoted H subset G or H<G.