% README % xint 1.4o % 2025/09/06

Source:  xint.dtx 1.4o 2025/09/06
Author:  Jean-François B.
Info:    Expandable operations on big integers, decimals, fractions
License: LPPL 1.3c

Description

The main functionality is \xintfloateval which parses expressions involving floating point numbers, functions, variables and other syntax elements.

The precision defaults to 16 decimal digits. The logarithm, exponential, direct and inverse trigonometric functions are supported up to 62 digits. The four basic operations and square-root extraction are implemented with correct rounding up to thousands of digits (roughly up to a maximum of 26000 digits for the output).

A variant \xinteval computes with fractions. And \xintiieval handles only (arbitarily large) integers.

All three parsers obtain their result purely expandably. They handle comma separated inputs and nested structures using square brackets. The user can declare custom variables and functions.

Usage

The way of loading xintexpr depends on whether you are using LaTeX or not.

• with LaTeX, add \usepackage{xintexpr} to the document preamble,
• else, do \input xintexpr.sty and compile with either one of etex, pdftex, xetex, luatex (they all default to the Plain TeX format), or with optex (i.e. luatex with OpTeX format), or with context (luametatex engine).

Example

Here is an example typical of the xintexpr users morning routine since many years (xintexpr was first released in 2013):

\xinteval{reduce(add(1/i^3, i=1..25))}

It expands (in two steps) to:

2560976152652211536408111110189/2131858131361319942957376000000

Repository

It is at https://github.com/jfbu/xint and the issue tracker is at https://github.com/jfbu/xint/issues.

Documentation

Both the user manual and the commented source code are in xint.pdf.

A file CHANGES.html is provided at https://jfbu.github.io/xint. Its source xintchanges.md is part of the CTAN upload, and you can access it in TeXLive using texdoc xintchanges.md.

Instructions for custom installation

The *sty files are extracted via the command etex xint.dtx. This produces also other files which (apart from this README.md) are of use only to build the PDF documentation. Either move them to the trash or check instructions in extracted xint.tex if you want to do the PDF build (spoiler: this can also be done exerting latex directly on xint.dtx...).

The recommended TeX directory structure is:

doc/generic/xint/xintchanges.md
doc/generic/xint/README.md
doc/generic/xint/xint.pdf
source/generic/xint/xint.dtx
tex/generic/xint/xint*sty

License

Copyright © 2013-2022, 2025 Jean-François B.

This Work may be distributed and/or modified under the conditions of the LaTeX Project Public License version 1.3c. This version of this license is in

http://www.latex-project.org/lppl/lppl-1-3c.txt

and version 1.3 or later is part of all distributions of LaTeX version 2005/12/01 or later.

This Work has the LPPL maintenance status author-maintained.

The Author of this Work is Jean-François B..

This Work consists of the file xint.dtx and README.md and their derived files such as xint.pdf.