Binomials

[sukiletxe]

According to MathML, mfrac also can be used for binomials. If the attribute linetickness is set to 0, it should be interpreted that way. Mathjax and Math Player do this too.

[tsengwoody]

May you provide some MathML example?

[sukiletxe]

Sure.

This is taken from http://www.pbx-brasil.com/Pesquisa/Ferramentas/Latex/mathjax/martinkeefe/mathjax5.html The original TeX is the annotation.

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <semantics>
    <mrow>
      <msup>
        <mn>2</mn>
        <mi>k</mi>
      </msup>
      <mo>&#x2212;<!-- − --></mo>
      <mrow>
        <mrow class="MJX-TeXAtom-OPEN">
          <mo maxsize="2.047em" minsize="2.047em">(</mo>
        </mrow>
        <mfrac linethickness="0">
          <mi>k</mi>
          <mn>1</mn>
        </mfrac>
        <mrow class="MJX-TeXAtom-CLOSE">
          <mo maxsize="2.047em" minsize="2.047em">)</mo>
        </mrow>
      </mrow>
      <msup>
        <mn>2</mn>
        <mrow class="MJX-TeXAtom-ORD">
          <mi>k</mi>
          <mo>&#x2212;<!-- − --></mo>
          <mn>1</mn>
        </mrow>
      </msup>
      <mo>+</mo>
      <mrow>
        <mrow class="MJX-TeXAtom-OPEN">
          <mo maxsize="2.047em" minsize="2.047em">(</mo>
        </mrow>
        <mfrac linethickness="0">
          <mi>k</mi>
          <mn>2</mn>
        </mfrac>
        <mrow class="MJX-TeXAtom-CLOSE">
          <mo maxsize="2.047em" minsize="2.047em">)</mo>
        </mrow>
      </mrow>
      <msup>
        <mn>2</mn>
        <mrow class="MJX-TeXAtom-ORD">
          <mi>k</mi>
          <mo>&#x2212;<!-- − --></mo>
          <mn>2</mn>
        </mrow>
      </msup>
    </mrow>
    <annotation encoding="application/x-tex">2^k-\binom{k}{1}2^{k-1}+\binom{k}{2}2^{k-2}</annotation>
  </semantics>
</math>

[tsengwoody]

OK, I will add rule for Binomial in future version.

[Futyn-Maker]

@sukiletxe Hello! To be honest, I don't understand in what cases this can be used. As I know, a binomial is a polynomial with two terms. Like (a + b)^2 and so on. What does mfrac mean in this rule?

[Futyn-Maker]

Oh, sorry for the confusion. The problem in the English word "binomial" which I translated in the same way as "binom". Now I understand that it means binomial coefficient...

[tsengwoody]

Binomial rule is added in math rule.