∀ (equalMVarIds : Std.HashMap Lean.MVarId Lean.MVarId) (equalLMVarIds : Std.HashMap Lean.LMVarId Lean.LMVarId)
  (leftUnassignedMVarValues rightUnassignedMVarValues : Std.HashMap Lean.MVarId Lean.Expr),
  sizeOf
      { equalMVarIds := equalMVarIds, equalLMVarIds := equalLMVarIds,
        leftUnassignedMVarValues := leftUnassignedMVarValues, rightUnassignedMVarValues := rightUnassignedMVarValues } =
    1 + sizeOf equalMVarIds + sizeOf equalLMVarIds + sizeOf leftUnassignedMVarValues + sizeOf rightUnassignedMVarValues