The use of finite-segmentp-adic arithmetic for exact computation

A finite number system for doing exact computer arithmetic, due to Krishnamurthy, Rao, and Subramanian, is described. For each rational numbera/b, with |a| and |b| suitably bounded, the firstr digits of the (infinite)p-adic expansion ofa/b are used as a coded representation fora/b (the Hensel code). Arithmetic operations on the Hensel codes produce Hensel codes for the exact results of the arithmetic operations.