prodigy: PRObability DIstributions via GeneratingfunctionologY

prodigy is a prototypical tool for the analysis of probabilistic non-negative integer programs with while-loops. It is based on (probability) generating functions.

It provides a command-line interface and a web GUI.

Contents

1. Installation
2. Basic Usage

Installation

With pip

Prodigy is on PyPI as prodigy-ppl (the command and the Python package are called prodigy):

pip install prodigy-ppl

This needs Python 3.11 or newer and contains the SymPy, SymEngine and the faster GiNaC engine (--engine ginac). The GiNaC engine comes from prodigy-ppl-ginac, whose wheels bundle GiNaC; pip installs it on Linux (x86_64, aarch64, glibc) and macOS with Python 3.11–3.14. Elsewhere, the extra ginac builds it from source, which needs a C++17 compiler, CMake and GiNaC:

pip install "prodigy-ppl[ginac]"

With Docker

The image contains the command line and the web GUI with the SymPy, GiNaC and SymEngine engines, for amd64 and arm64 (tags: version, e.g. 3.1.0, minor version 3.1, and latest). Without arguments it starts the web GUI on http://localhost:8080:

docker run --rm -p 8080:8080 ghcr.io/lklinke/prodigy

Arguments are passed to prodigy; mount the folder with your programs to use the command line:

docker run --rm -v "$PWD":/work ghcr.io/lklinke/prodigy main /work/example.pgcl

Dockerfile.artifact builds the full environment for artifacts (all engines including GiNaC, the sources and the development tools): make docker-artifact, then docker run -ti prodigy-artifact.

From source

To install Prodigy from the repository, follow these steps:

1. Make sure Python 3.11 or newer is installed (tested with 3.11 and 3.14).
2. Install uv.
3. Clone or download the Prodigy repository, open a command prompt in its root folder, and type ./install.sh. This installs Prodigy with the dependency versions locked in uv.lock into .venv, and the Z3 solver for pysmt.

If no errors occurred, you have successfully installed Prodigy. Now there are two options on how to use the tool. You can either use the command-line interface (CLI) or the web GUI. The next section (Basic Usage) details how to achieve both of these things.

Troubleshooting

If you run into trouble during installation, this subsection might be of help. It lists some common problems that might occur during installation of Prodigy and how you can (hopefully) solve them.

• If you're using Windows, don't (not even WSL). We heavily recommend using either Linux or MacOS, as some of the required libraries have compatibility problems with Windows.
• If pip builds prodigy-ppl-ginac from source (no wheel for your platform, e.g. Alpine Linux), install GiNaC and make sure all of these packages are installed (if you're not using a Debian/Ubuntu based distribution, these might differ slightly):
  • CMake
  • pkg-config
  • build-essential (includes make, g++, gcc, and more)
  • python3-dev (called python3-devel on some other package managers such as yam)

Basic Usage

CLI

1. In the project directory, run prodigy with uv run prodigy ... (or activate the virtual environment with source .venv/bin/activate and type prodigy ...).
2. For more information, see the help message (uv run prodigy --help) or have a look into the documentation.

Web GUI

1. Type uv run prodigy web (or uv run prodigy --engine ginac web for the faster GiNaC engine). The GUI opens in your browser.
2. Write or load a program, choose a strategy for each loop under Setup, and press Analyze (⌘/Ctrl + Return).

Results come with their guarantee (exact, lower bound with residual mass, upper bound), and queries are answered with sound intervals. See docs/gui.md, which also describes the non-interactive analysis API (prodigy analyze --json).

Development

• make lint, make mypy and make test run the checks of the CI (pylint, mypy, and the tests with coverage; see .github/workflows/main.yml).
• Releases: bump version in pyproject.toml, merge, and push a tag v<version> (e.g. v3.1.0). .github/workflows/release.yml runs the checks, waits for approval in the environment release, and publishes to PyPI, the Docker image (Dockerfile) to ghcr.io, and a GitHub release.
• Dependencies are locked in uv.lock. After changing them in pyproject.toml, run uv lock and commit both files. uv lock --upgrade updates all dependencies within their constraints; Dependabot proposes such updates monthly as pull requests.