→ math1209:反證:若 liminf a_n := a < b, 則...顯然產生矛盾 12/23 12:59
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.136.133.8
Let {a_n} be a sequence of real numbers, if for every subsequence {a_n_k}
there exists a further subsequence {a_n_k_j} with liminf a_n_k_j >= b,
then liminf a_n >= b.
thanks in advance.
--