1)THEOREM 5: If g is a function discontinuous at the rationals and continuous at the irrationals, then there is a dense uncountable subset of the reals at each point of which g fails to satisfy a Lipschitz condition.
2)「系1.8 有理数の点で不連続、 無理数の点で微分可能となるf : R → R は存在しない」
この二つの比較で、2)の”無理数の点で微分可能”なら、1)THEOREM 5の”continuous at the irrationals”は、満たされる ”there is a dense uncountable subset of the reals at each point of which g fails to satisfy a Lipschitz condition.”から、有理点以外で必ず”at each point of which g fails to satisfy a Lipschitz condition”なる（無理）点が存在する その（無理）点は、微分不能
