A Principled Approach to Version Control

Version control systems are essential for managing the distributed development of large software projects. We present a formal model for reasoning about version control. In particular, we give a general definition of patch. Patches abstract over the data on which they operate, making our framework equally suited for version control of everything from highly-structured XML files to blobs of bits. We model repositories as a multiset of patches. The mathematical definitions of patches and repositories enable us to reason about complicated issues such as conflicts and conflict resolution.