毒 is a subset of 連登
but 毒 is not a superset of 連登
Therefore, 毒 is not equal to 連登
我愛陳嘉靖2018-12-06 22:57:35
我愛陳嘉靖2018-12-06 23:06:28
Prove 毒撚 is an accumulation point of 連登:
For all 毒撚 belongs to 連登, there exist an open ball centered at 毒撚 with radius greater than 0 contains a point in 連登, which is obviously true because 毒撚 is a subset of 連登.