Compared with proposition logic and quantifier logic, logic of syllogism is more special, and the validity of valid mood of syllogism can not be all illustrated with general quantifier logic.

• 三段论逻辑，是比命题逻辑、量词逻辑更为特殊的逻辑，用一般的量词逻辑是无法说明所有三段论有效式的有效性的。