FLINT3.7.0-dev
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User guide

The user guide explains how to install FLINT, how to compile programs against it, and conventions that all modules share: word types, naming of functions, aliasing, memory management, multithreading, portability, error handling, and generic programming.

The guide then explains what FLINT guarantees and what it does not: which algorithms are proved correct, how FLINT is tested, which inputs are checked, and limitations. It helps choose among FLINT's many types for a task and explains rigorous ball arithmetic. It also describes interfaces to other languages and explains how to report bugs and contribute.

New users should start with Introduction and Building, testing and installing, and then follow the first tutorial, A first program. The release notes of all versions are in History.

Getting started

What FLINT is, how to build and install it, and how to compile programs against it.

User guideIntroductionWhat FLINT is, what it contains, how the library and its documentation are organised, what it requires, and its license.User guideBuilding, testing and installingHow to configure, build, test and install FLINT with the Autotools build system (or CMake on Windows), the configuration options, and how to compile and link programs against the installed library.

Conventions

Types, naming, aliasing, memory management, threading and portability rules shared by all modules.

User guideTypes, naming and aliasingThe word types, how FLINT objects are declared and passed, how functions are named, what the leading underscore means, the aliasing rules and the normalisation of objects.User guideMemory managementInitialising and clearing objects, FLINT's allocation functions, temporary allocation, the caches FLINT keeps and how to free them, and custom allocators.User guideThreadsHow to let FLINT use several threads, which operations are parallelised, the rules for calling FLINT from several threads, and the conventions for writing threaded functions.User guidePortabilityWriting code with FLINT that works on 32-bit and 64-bit platforms and on Windows: word types, constants, printing and the platform-dependent parts of the library.

Correctness

What FLINT guarantees about its results, how it is tested, which inputs are valid, size limits, and why FLINT must not be used for cryptography or on untrusted data.

User guideWhat FLINT guaranteesProvably correct algorithms as the rule; the documented exceptions (probable primes, Monte Carlo methods, conjectures, floating point); randomised algorithms with certified output; and answers that may be "unknown".User guideTesting, bugs and checking resultsHow FLINT is tested, why bugs that give wrong results still occur, how to check results independently, debug builds with assertions, and how to report a bug.User guideInvalid inputWhy most FLINT functions do not check their input, which classes of functions do check (and how they report errors), and typical preconditions that are not checked.User guideSizes and limitsWhy lengths, shift counts, exponents and precisions are not checked for overflow, examples of what goes wrong with huge or negative values, the size limits inherited from GMP, exponent ranges, and what happens when memory runs out.User guideSecurityFLINT is a library for mathematical research, education and experimentation; why it must not be used to implement cryptographic protocols, and why untrusted input should only be processed in a sandbox.

Types and mathematical domains

Which FLINT type to use for integers, residues, finite fields, polynomials, matrices, p-adic, algebraic, real and complex numbers; ball arithmetic and exact real and complex numbers.

User guideChoosing typesHow to choose among FLINT's types for integers, residues, finite fields, polynomials, matrices, p-adic and algebraic numbers, real and complex numbers and power series, with their limits, their performance and the generic alternative.User guideBall arithmeticRigorous real and complex arithmetic with balls: the inclusion principle, printing, overestimation, predicates, precision and accuracy, the guess-and-verify strategy, and the conventions specific to the ball types.

Generic programming

The techniques FLINT uses to implement one algorithm for many types (parallel modules, preprocessor templates, generated code, run-time dispatch and the generic rings of gr), and what the generic interface costs compared with the type-specific modules.

Interfaces

Using FLINT from other languages.

User guidePython interfacesUsing FLINT from Python, with the separate python-flint package or the experimental flint_ctypes wrapper included with FLINT.

Development

Contributing code, reporting bugs, and the contributors to FLINT.

User guideContributing to FLINTHow to add a function to FLINT: source, header, test and documentation, the code style, how to write good test code, and how to submit changes.User guideReporting bugsWhere to report bugs in FLINT and what information to include.User guideContributorsThe people who have written FLINT, and where to find the complete list of contributors.
Cite this page

The FLINT team, “User guide,” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/guide/index.html (generated 2026-10-20).