This package contains libraries with data types for a binary representation of natural and integer numbers. It is based on the paper *Declaring Numbers* by Brassel/Fischer/Huch ENTS 216, 2008.

The advantage of this algebraic definition in contrast to built-in integers is the possibility to use them also for narrowing, i.e., functional logic programming. Since the operations are also quite efficient compared to a simple Peano representations, this library is also the basis of the implementation of integers in the Curry implementation KiCS2.