Definition compatVersionChangeMax
  (x y : compatVersionChange) 
: compatVersionChange :=
  match (x, y) with
  | (CVersionChangeMajor , _                  ) => CVersionChangeMajor
  | (_                   , CVersionChangeMajor) => CVersionChangeMajor
  | (CVersionChangeMinor , CVersionChangeNone ) => CVersionChangeMinor
  | (CVersionChangeNone  , CVersionChangeMinor) => CVersionChangeMinor
  | (CVersionChangeMinor , CVersionChangeMinor) => CVersionChangeMinor
  | (CVersionChangeNone  , CVersionChangeNone ) => CVersionChangeNone
  end.
