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{
  "uri": "at://did:plc:g7zfvo5t5ont4ejo4owoaiav/app.bsky.feed.post/3ljltpeagzk2b",
  "cid": "bafyreigw35z7l63vbver2i63ma5gnatevibt67fp5zez6giv6xp3ets6ly",
  "value": {
    "text": "A simple example is BU(1) = CP^infty, and H*(CP^infty, Z) = Z[[x]] with x in H^2. This is the first Chern class of a line bundle! More generally, BO(n) is an infinite Grassmannian, and H*(BO(n), Z/2) is the free polynomial algebra over Z/2 generated by the first n Stiefel Whitney classes.",
    "$type": "app.bsky.feed.post",
    "langs": [
      "en"
    ],
    "reply": {
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        "uri": "at://did:plc:g7zfvo5t5ont4ejo4owoaiav/app.bsky.feed.post/3ljltkcns3k2b"
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      "parent": {
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        "uri": "at://did:plc:g7zfvo5t5ont4ejo4owoaiav/app.bsky.feed.post/3ljltkcns3k2b"
      }
    },
    "createdAt": "2025-03-05T01:36:21.207Z"
  }
}