Developed a formal equivalence definition for constraint systems in optimization within the powdr-labs/powdr repository, establishing a rigorous foundation for determining when two intermediate representations can be considered interchangeable. This work leveraged formal methods and documentation skills to clarify how constraint interactions affect optimization flows, directly supporting more robust reasoning about IR transformations. The approach involved close collaboration with other contributors to ensure the definition was broadly applicable and well-documented in Markdown. By aligning the optimizer documentation with the new equivalence concept, the contribution laid essential groundwork for future optimization passes and improved maintainability of the repository’s constraint system tooling.