∀ (goal : Aesop.GoalRef) (priority : Aesop.Percent) (lastExpandedInIteration addedInIteration : Aesop.Iteration),
  sizeOf
      { goal := goal, priority := priority, lastExpandedInIteration := lastExpandedInIteration,
        addedInIteration := addedInIteration } =
    1 + sizeOf goal + sizeOf priority + sizeOf lastExpandedInIteration + sizeOf addedInIteration