5 \item $N$ and $D$ are arbitrary precision integers
8 N &= \sum_{i=0}^{S} d_i \beta^{i}
11 \item $d_i$ are fixed size integers, $\beta = 2^{64}$
12 \item Size $S$ grows as needed
13 \item Operations are always exact
14 \item Implemented by GNU Multiple Precision Library