Worked on improving documentation quality in the opencompl/lean4 repository, focusing on enhancing the accuracy of API references for Lean. Delivered a documentation-only update by correcting a typo in the mkMVar docstring within Lean/Expr.lean, changing mkFresheExprMVar to mkFreshExprMVar. This change did not alter any code behavior or introduce functional modifications, ensuring runtime stability while clarifying developer-facing documentation. The update supports better onboarding for new contributors and improves long-term maintainability of the codebase. Utilized skills in documentation and familiarity with the Lean language to ensure that technical references remain precise and accessible for future development efforts.