Worked on improving the rust-lang/rustc-dev-guide repository by updating and refining technical documentation related to FnOnce implied bounds. Focused on enhancing documentation accuracy and maintainability, the work involved removing outdated explanations from invariants.md and clarifying the current understanding of implied bounds invariants for contributors. The update was implemented using Markdown, leveraging strong documentation skills to ensure clarity and relevance for future readers. No bug fixes were addressed during this period, as the primary emphasis was on documentation quality. The contribution provided a more accurate reference for developers working with Rust, supporting ongoing efforts to keep project documentation up to date.