_di_below, _di_above
Synopsis
#include <flint/double_interval.h>double _di_below(double x)sourcedouble _di_above(double x)sourceReturn a lower respectively upper bound for any real number whose round-to-nearest value is x. _di_below returns x - (|x| + 10^{-300}) \cdot 2^{-51} for x \le 10^{300} (rounded to nearest), 10^{300} for larger x including +\infty, and -\infty for NaN (which arises from \infty - \infty in the endpoint arithmetic); _di_above is symmetric.
Cite this page
The FLINT team, “_di_below, _di_above (double_interval.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/double_interval/_di_below.html (generated 2026-10-20).
@misc{flint-doc-double-interval-di-below,
author = {{The FLINT team}},
title = {{\_di\_below, \_di\_above (double\_interval.h)}},
howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
year = {2026},
url = {https://flintlib.org/doc/double_interval/_di_below.html},
note = {Generated 2026-10-20}
}