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  "body": "\n## Summary\n\nInformally, a **definable real number** is a [[real number|08J2M1JYAG]] that can be uniquely specified by its description. The description may be expressed as a construction or as a formula of a formal language. For example, the positive square root of 2, $\\sqrt{2}$, can be defined as the unique positive solution to the equation $x^2 = 2$, and it can be constructed with a compass and straightedge.\n",
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