This package defines a new abstract type, ThickNumber{T}, which is like Julia's Number but represents numbers that may have a "thickness" or "width". Such numbers generally support arithmetic but also act like sets, in the sense that they contain spans of "point" numbers. Prominent examples of such numbers include intervals and gaussian random variables.
It also defines a common API for working with ThickNumber types, making it possible to write code that supports multiple ThickNumber subtypes simultaneously. See the documentation for details.