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  "body": "\n## Definition\n\nLet $f \\colon A \\to B$ be a [[function|0XHDTE5YMZ]].\nA right inverse of $f$ is a function $h \\colon B \\to A$ such that $f \\circ h = \\mathrm{id}_B$, that is, $f(h(b)) = b$ for each $b \\in B$.\n\n## Remarks\n\nA function has a right inverse exactly when it is [[surjective|0XKH881BZ7]]. The proof uses the [[axiom of choice|0HTGB13FE2]]. See [[surjective iff it has a right inverse|0TYQNHVB4C]].\nA right inverse is in general not unique.\nA right inverse is [[injective|0PVG1CRAJN]].\n\n## Explanations\n\n### L1 human\n\nFor $f(x) = x^2$ from $\\mathbb{R}$ to $[0, \\infty)$, the square root $h(y) = \\sqrt{y}$ is a right inverse: $(\\sqrt{y})^2 = y$.\nThe function $y \\mapsto -\\sqrt{y}$ is another right inverse.\n",
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