Recurse Center - GoKawiil

Developer recounts summer projects at Recurse Center programming retreat

A programmer spent a summer at Recurse Center, a Brooklyn-based self-directed coding retreat, participating in peer-led study groups. Activities included an 'Agentic Adventures' group exploring LLM agents and sandboxed coding environments, a 'Practical Deep Learning' group working through Jeremy Howard's book, and a 'Math Monday' discussion group started with another attendee. Projects included building a remote sandbox for a coding agent, training a small text-prediction model on Romeo and Juliet, and experimenting with LoRA fine-tuning.

thill.me · 2026-09-27

Rocq formalization exposes edge-case flaw in Dummit and Foote's Abstract Algebra

While formalizing Dummit and Foote's algebra textbook in the Rocq proof assistant, a Recurse Center participant found that the book's first proof exercise—claiming a function is injective if and only if it has a left inverse—fails when the domain is empty and the codomain is not. In that case the empty function is vacuously injective but has no left inverse, since no function can map from a nonempty codomain to an empty domain. The author later confirmed the issue is already listed in the book's published errata.

kallus.org · 2026-09-04