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  "body": "\n## Summary\n\nA set $A$ is Turing reducible to a set $B$ if some [[oracle machine|Z5CCVBME2V]] decides membership in $A$ by asking questions about $B$.\nIt is the most general notion of \"$A$ is computable from $B$\" in computability theory.\nTuring reducibility is the basis of Turing degrees, which measure the amount of uncomputability of a set.\n\n## Explanations\n\n### L1 human\n\nImagine a computer that has a magic helper: whenever it asks \"is this number in $B$?\", the helper answers at once.\nIf such a computer can always decide whether a number lies in $A$, then $A$ is Turing reducible to $B$.\nThe computer may ask many questions, and later questions may depend on earlier answers.\nFor example, the complement of a set $B$ is Turing reducible to $B$: ask whether $x \\in B$ and flip the answer.\nThis is more freedom than a [[many-one reduction|JTAH37JTHD]], which asks only one question and must copy its answer.\n",
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