J'(k x) := (J(k x))'이고,

J''(k x) := (J'(k x))'이라니,

정말 어이가 없네 ㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋㅋ