Bramble-Hilbert lemma
...that in numerical analysis, the error of an approximation of a function u {\displaystyle \textstyle u} by a polynomial of order at most m − 1 {\displaystyle \textstyle m-1} in terms of derivatives of u {\displaystyle \textstyle u} of order m {\displaystyle \textstyle m} is bound by the Bramble-Hilbert lemma?
...that in <a href="./Numerical_analysis" id="mwFSY" rel="mw:WikiLink" title="Numerical analysis">numerical analysis</a>, the <a href="./Approximation_error" id="mwFSc" rel="mw:WikiLink" title="Approximation error">error of an approximation</a> of a <a href="./Function_(mathematics)" id="mwFSg" rel="mw:WikiLink" title="Function (mathematics)">function</a> <span about="#mwt19" class="mwe-math-element" data-mw='{"name":"math","attrs":{},"body":{"extsrc":"\\textstyle u"}}' id="mwFSk" typeof="mw:Extension/math"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math alttext="{\displaystyle \textstyle u}" xmlns="http://www.w3.org/1998/Math/MathML">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mstyle displaystyle="false" scriptlevel="0">
<mi>u</mi>
</mstyle>
</mstyle>
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<annotation encoding="application/x-tex">{\displaystyle \textstyle u}</annotation>
</semantics>
</math></span><img alt="{\displaystyle \textstyle u}" aria-hidden="true" class="mwe-math-fallback-image-inline mw-invert" src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a6199e6db6b10b31b728e94d27e30cb974562e53" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;"/></span> by a <a href="./Polynomial" id="mwFSo" rel="mw:WikiLink" title="Polynomial">polynomial</a> of order at most <span about="#mwt20" class="mwe-math-element" data-mw='{"name":"math","attrs":{},"body":{"extsrc":"\\textstyle m-1"}}' id="mwFSs" typeof="mw:Extension/math"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math alttext="{\displaystyle \textstyle m-1}" xmlns="http://www.w3.org/1998/Math/MathML">
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<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
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<mi>m</mi>
<mo>−<!-- − --></mo>
<mn>1</mn>
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<annotation encoding="application/x-tex">{\displaystyle \textstyle m-1}</annotation>
</semantics>
</math></span><img alt="{\displaystyle \textstyle m-1}" aria-hidden="true" class="mwe-math-fallback-image-inline mw-invert" src="https://wikimedia.org/api/rest_v1/media/math/render/svg/043abd421749b37b31cf2fe59f5b15e970be076e" style="vertical-align: -0.505ex; width:6.043ex; height:2.343ex;"/></span> in terms of <a class="mw-redirect" href="./Derivative_(mathematics)" id="mwFSw" rel="mw:WikiLink" title="Derivative (mathematics)">derivatives</a> of <span about="#mwt21" class="mwe-math-element" data-mw='{"name":"math","attrs":{},"body":{"extsrc":"\\textstyle u"}}' id="mwFS0" typeof="mw:Extension/math"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math alttext="{\displaystyle \textstyle u}" xmlns="http://www.w3.org/1998/Math/MathML">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mstyle displaystyle="false" scriptlevel="0">
<mi>u</mi>
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<annotation encoding="application/x-tex">{\displaystyle \textstyle u}</annotation>
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</math></span><img alt="{\displaystyle \textstyle u}" aria-hidden="true" class="mwe-math-fallback-image-inline mw-invert" src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a6199e6db6b10b31b728e94d27e30cb974562e53" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;"/></span> of order <span about="#mwt22" class="mwe-math-element" data-mw='{"name":"math","attrs":{},"body":{"extsrc":"\\textstyle m"}}' id="mwFS4" typeof="mw:Extension/math"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math alttext="{\displaystyle \textstyle m}" xmlns="http://www.w3.org/1998/Math/MathML">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mstyle displaystyle="false" scriptlevel="0">
<mi>m</mi>
</mstyle>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \textstyle m}</annotation>
</semantics>
</math></span><img alt="{\displaystyle \textstyle m}" aria-hidden="true" class="mwe-math-fallback-image-inline mw-invert" src="https://wikimedia.org/api/rest_v1/media/math/render/svg/fa35069f79eaab8d7586d629e6a9e4d2906cfe3b" style="vertical-align: -0.338ex; width:2.04ex; height:1.676ex;"/></span> is bound by the <b id="mwFS8"><a class="mw-redirect" href="./Bramble-Hilbert_lemma" id="mwFTA" rel="mw:WikiLink" title="Bramble-Hilbert lemma">Bramble-Hilbert lemma</a></b>?