The Spectre KnotMade with AI
How this was made

Made with AI: an experiment

The Spectre Knot is an experiment in using AI for mathematical exploration. Justin Roughley came up with the original idea of looking for a mono‑stranded aperiodic knot, and then used AI to search for it. From then on an AI system (Claude, by Anthropic) did the detailed work at every stage, always at his instruction: it generated the programs, the proofs of the two theorems, a formal version of the proof that the Lean proof assistant checks, the paper, this website and the handout. He set the direction, made the choices, questioned the work and had it corrected. Justin Roughley is the author, and is responsible for the work, including its correctness; the AI is not an author.

The status of the proof

The proofs and the Lean were generated by the AI at Justin Roughley’s instruction. Lean checks the combinatorial heart of the proof; the step linking it to actual tilings of the plane (how real supertiles fit together) is argued in words. Justin Roughley has read parts of the paper and spot-checked pictures and counts; most of the proof has not been reviewed by a human, and no professional mathematician has reviewed it. No human has checked that the Lean’s statements say what the theorems say. The paper has not been peer reviewed.

AI can turn out a great deal of plausible-looking mathematics very quickly. That is why the proof was also written for Lean, whose checker verifies every step mechanically, and why this page sets out plainly who did what.

Who did what

WhatJustin RoughleyThe AI system, at his instruction
The questionAsked it: is there a one‑strand knot that covers the plane?–
Searching for designsAsked for the search and steered itGenerated and ran the search programs, which found 34 candidate designs
Design 0.1:01Chose it, drew its ribbons by hand, and chose the offset of the crossing points along the edgesGenerated the tile editor he drew it in
The computations, up to 133 million tilesAsked for themGenerated and ran the programs
The proofs of the two theoremsAsked for a proof; directed the work, questioned it and asked for corrections; decides what is claimedGenerated the proofs: the method, the lemmas and the arguments
A formal version of the proof’s combinatorial part, for the Lean proof assistantAsked for itGenerated it; Lean checked every step
The paper setting out the proofsDirected it, and specified that it follow the Leiden Declaration on artificial intelligence and mathematicsGenerated the text and the figures
Naming the theorems and lemmas (the Daedalus Theorem, the Ariadne Theorem, the Signature Theorem; the Zigzag and Grandparent Lemmas)Chose the namesSuggested names
This website, the handout and the tileSet the brief, made the decisions and asked for changesGenerated them
Checking the proofRead parts of the paper and spot-checked pictures and countsReviewed the argument in several passes; generated the second programs used as checks
Credit and responsibilityHis alone: he is the authorNone: it is a tool, not an author

No professional mathematician has reviewed the proof. An AI system builds on mathematics that people have published: the work this rests on is credited on About and in the paper, and the paper says that it may use an idea whose source it does not cite.

What has been checked

What has been checked, by Lean, by computer, by the AI and by Justin Roughley, and what has not, is set out on the proof site: What has been checked. On this site, the Prove page marks each step as cited from the spectre paper, computed, or argued in words, with a Lean tag where Lean also checks it, and says exactly which tilings each theorem covers. Every program, including the second or separate ones used as checks, and the Lean, was generated by the same AI system. Every tool used is listed in the paper’s Tool and computational resource disclosure.