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.
The most basic relations in set theory can be summarized as follows. 1  A set S1 is a subset of set S if and only if every element of S1 is also an element of S. 2  A set S1 is a proper subset of set S if and only if every element of S1 is also an element of S, but there are some elements in S that are not elements of S1.