Proposed resolution:

In [concept.arithmetic], add to the list of less refined concepts one further concept:

concept ArithmeticLike<typename T>
  : Regular<T>, LessThanComparable<T>, HasUnaryPlus<T>, HasNegate<T>,
    HasPlus<T, T>, HasMinus<T, T>, HasMultiply<T, T>, HasDivide<T, T>,
    HasPreincrement<T>, HasPostincrement<T>, HasPredecrement<T>,
    HasPostdecrement<T>,
    HasPlusAssign<T, const T&>, HasMinusAssign<T, const T&>,
    HasMultiplyAssign<T, const T&>,
    HasDivideAssign<T, const T&>, ExplicitlyConvertible<T, bool> {