I turned the freshly published paper “The Constructor Theory of Time” by David Deutsch and Chiara Marletto (arXiv, 13 May 2025) into an executable Python library.

What you’ll find • One-to-one translation of the paper’s formalism: Substrates, Attributes, Tasks, Constructors, and task-algebra operators • Possibility / impossibility predicates and counterfactuals encoded exactly as defined • Test suite that mirrors every lemma and example (>95 % coverage, mypy-typed) • Reproductions of key results: time-keeping substrates, irreversibility proofs, quantum branching tasks, and a self-replicating constructor

Why share? Reading the paper is tough going; expressing each definition in code clarified the ideas and surfaced a couple of questions for discussion. Hoping it helps others and sparks extensions.

Looking for feedback: • Did I miss any subtleties in the formalism? • Which additional theorems or examples would you like implemented next?

Repo: https://github.com/gvelesandro/constructor-theory-simulator

Thanks for taking a look—issues and PRs welcome!