Haskell library to work with positive integers (i.e. 1, 2, 3, ...).
Some people call these the natural numbers.
However, others include 0 as a natural number.
The term positive integer is always clear.
Besides, Natural is a widely used type in Haskell (and it has 0 in it).
In addition to functions strictly related to positive integers, functions for non-empty lists that take advantage of having positive integers available are also included. See Haddock documentation on Hackage for details.