Infinity comes up in many aspects of mathematical discourse and is often treated as a number, but it is not a [[real number]]. In mathematical contexts, infinity often appears as a limit, as an integral, as the measure (size) of a set in Euclidean space, and as the cardinality (size) of sets in general. | Infinity comes up in many aspects of mathematical discourse and is often treated as a number, but it is not a [[real number]]. In mathematical contexts, infinity often appears as a limit, as an integral, as the measure (size) of a set in Euclidean space, and as the cardinality (size) of sets in general. |