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  "body": "\n## Summary\n\nA Fréchet–Urysohn space is a topological space with the following property.\nEach point of the closure of a set is the limit of a sequence from that set.\nSo closures, and not only closed sets, can be computed with sequences.\nEvery [[first-countable space|0CP5NDD21C]] is Fréchet–Urysohn, and every Fréchet–Urysohn space is [[sequential|WMB2MAEDX4]].\nThe converse implications fail in general.\n\n## Explanations\n\n### L1 human\n\nIn a metric space, a point is in the closure of a set exactly when some sequence from the set runs to it.\nA Fréchet–Urysohn space is a space where this familiar fact still holds.\nFor example, in $\\R$ the point $\\sqrt 2$ is in the closure of $\\Q$, and the decimal approximations $1, 1.4, 1.41, \\ldots$ form a sequence of rationals that converges to it.\n",
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