Worked on enhancing the correctness and reliability of symbolic simplification in the sympy/sympy repository, focusing on the radsimp module’s fraction handling under strict mode. Addressed a bug affecting Pow expressions by implementing a targeted fix in Python, ensuring that fraction(Pow(2, -2, evaluate=False), exact=True) returns the mathematically correct result. Added regression tests to cover strict-mode behavior, reducing the risk of future regressions and maintaining performance. Emphasized debugging, symbolic computation, and regression-driven development to improve the reliability of exact arithmetic paths. The work contributed to more trustworthy symbolic results and strengthened the codebase’s resilience against future changes.