Now what the people widely use is the SDL system (standard deontic logic system), but the SDL system receives a series of paradoxes, in which most lets the logician headache is the CTD paradox.

现在人们广泛使用的是SDL系统(标准道义逻辑系统)，但SDL系统都受到一系列悖论的困扰，其中最让逻辑学家头痛的就是CTD悖论。

youdao

Now what the people widely use is the SDL system (standard deontic logic system), but the SDL system receives a series of paradoxes, in which most lets the logician headache is the CTD paradox.

现在人们广泛使用的是SDL系统(标准道义逻辑系统)，但SDL系统都受到一系列悖论的困扰，其中最让逻辑学家头痛的就是CTD悖论。

youdao