I am trying to prove that zero is in the weak closure of set $\{ x\in l^1 \,:\, \lVert x\rVert =1\}$ . And I need example too. Is there any countable subset of this set which has $0$ in weak closure?
2026-04-20 02:33:10.1776652390
Weak closure of the boundary of the unit ball of $l^1$
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