  Arb is a C library for arbitrary-precision interval arithmetic using the
midpoint-radius representation, also known as ball arithmetic. It supports real
and complex numbers, polynomials, power series, matrices, and evaluation of
many special functions. The core number types are designed for versatility and
speed in a range of scenarios, allowing performance that is competitive with
non-interval arbitrary-precision types such as MPFR and MPC floating-point
numbers. We discuss the low-level number representation, strategies for
precision and error bounds, and the implementation of efficient polynomial
arithmetic with interval coefficients.
