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 set A is said to be a subset of a set B, if every element of A is also an element of B. In other words, $A \subset B$ if whenever $a \in A$, then $a \in B$. It is often convenient to use the symbol $\Rightarrow$ which means implies. Using the symbol $\Rightarrow$, we can write the definition of subset as follows: $A \subset B$ if $a \in A \Rightarrow a \in B$. We read it as A is a subset of B if a is an element of A, which implies that a is also an element of B.