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█ ██ ██ ◥▆▆ ███ ◢◤█ 摸狗狗退散 ▇▅▄▆
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※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.218.142
Suppose that X is contained in Y, and Y is contained in Z,
where X, Y, and Z all are metric spaces. Show that X is compact
relative to Y iff X is compact relative to Z.
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