Axiom of foundational原來文句反而我明,但點解簡單版會唔明
例如話
呢啲S={{a}}, 必然有個a belongs to {a} belongs to S, 即a belongs to S,而a就是minimal element(there must exist x such that no set y belongs to it),即係話有minimal element m、唔可以再有嘢belongs to m嘅non-empty set係可以存在嘅,其餘就唔得
所以不可能存在無限bracket,因為要有最基本元素
但反而當佢話a intersects with S is empty,(原因我估仍然因為a唔係集合)
但係a intersects with S 唔係應該係ill-defined(intersection要求兩邊係集合),點解係empty?