1. The Baire category theorem - Aarhus Universitet
1. The Baire category theorem - Aarhus Universitet
1. The Baire category theorem - Aarhus Universitet
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Proof of <strong>Baire</strong>’s <strong>category</strong> <strong>theorem</strong> - continued<br />
<strong>The</strong> proof is now completed as follows; first the case when S is a<br />
locally compact Hausdorff space:<br />
B0 ⊇ B1 ⊇ B2 ⊇ B3 ⊇ ... and each Bk,k ≥ 1, is compact and<br />
non-empty.<br />
It follows that ∞ k=1 Bk = ∅. Since Bk ⊆ Vk−1 for all k, we find<br />
that<br />
∞ ∞<br />
Vk.<br />
k=1<br />
Bk ⊆<br />
But ∞<br />
k=1 Bk ⊆ B0, so we see that<br />
∞<br />
k=1<br />
Bk ⊆<br />
k=0<br />
∞<br />
Vk ∩ B0,<br />
k=1<br />
which was what we wanted to prove.<br />
Klaus Thomsen <strong>1.</strong> <strong>The</strong> <strong>Baire</strong> <strong>category</strong> <strong>theorem</strong>