MathML Fundamentals - Operator mo stretchy

An mo element represents an operator or anything that should be rendered as an operator. In MathML the list of things that should "render as an operator" includes a number of notations that are not mathematical operators in the ordinary sense. Besides ordinary operators with infix, prefix, or postfix forms, these include fence characters such as braces, parentheses, and "absolute value" bars; separators such as comma and semicolon; and mathematical accents such as a bar or tilde over a symbol. MathML Fundamentals

very long + ... + texttttttttttttt k times very long + ... + texttttttttttttt k times very long + ... + texttttttttttttt k times k very long + ... + texttttttttttttt 2 very long + ... + texttttttttttttt 23 very long + ... + texttttttttttttt 2 233 very long + ... + texttttttttttttt 233 2 very long + ... + texttttttttttttt i j k l 0 12 12 very long + ... + texttttttttttttt very + + text very long + ... + texttttttttttttt x + + + + y very long + ... + texttttttttttttt x + + + + y very long + ... + texttttttttttttt x + + + + y

MathML

<math display="block">
    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover style="border:1px">
          <mrow style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <mover  style="border:1px">
            <mo style="border:2px">⏞</mo>
            <mrow><mi>k</mi> <mspace width="thinmathspace"></mspace> <mtext>times</mtext></mrow>
          </mover>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover style="border:1px">
          <mrow style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <munder  style="border:1px">
            <mo style="border:2px">⏞</mo>
            <mrow><mi>k</mi> <mspace width="thinmathspace"></mspace> <mtext>times</mtext></mrow>
          </munder>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover style="border:1px">
          <mrow style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <munderover  style="border:1px">
            <mo style="border:2px">⏞</mo>
            <mrow><mi>k</mi> <mspace width="thinmathspace"></mspace> <mtext>times</mtext></mrow>
            <mi>k</mi>
          </munderover>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <msup  style="border:1px">
            <mo style="border:2px" >⏞</mo>
            <mi style="border:1px">2</mi>
          </msup>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <msub  style="border:1px">
            <mo style="border:2px" >⏞</mo>
            <mi style="border:1px">23</mi>
          </msub>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <msubsup  style="border:1px">
            <mo style="border:2px" >⏞</mo>
            <mi style="border:1px">2</mi>
            <mi style="border:1px">233</mi>
          </msubsup>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <msubsup  style="border:1px">
            <mo style="border:2px" >⏞</mo>
            <mi style="border:1px">233</mi>
            <mi style="border:1px">2</mi>
          </msubsup>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
		<mmultiscripts style="border:1px">
            <mo style="border:2px" >⏞</mo>
            <mi style="border:1px">i</mi>
            <none/>
            <none/>
            <mi style="border:1px">j</mi>
            <mi style="border:1px">k</mi>
            <none/>
            <mi style="border:1px">l</mi>
            <none/>
            <mprescripts/>
            <mn style="border:1px">0</mn>
            <mn style="border:1px">12</mn>
            <mn style="border:1px">12</mn>
            <none/>
        </mmultiscripts>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <mrow  style="border:1px">
            <mi>very</mi>
            <mo>+</mo>
            <mo style="border:2px" >→</mo>
            <mo>+</mo>
            <mi>text</mi>
          </mrow>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <mrow  style="border:1px">
            <mi>x</mi>
            <mo>+</mo>
            <mo style="border:2px" >→</mo>
            <mo>+</mo>
            <mo style="border:2px" >→</mo>
            <mo>+</mo>
            <mo style="border:2px" >→</mo>
            <mo>+</mo>
            <mi>y</mi>
          </mrow>
        </mover>

    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <mrow  style="border:1px">
            <mi>x</mi>
            <mo>+</mo>
            <mo style="border:2px" >→</mo>
            <mo>+</mo>
            <mo style="border:2px" stretchy="false">→</mo>
            <mo>+</mo>
            <mo style="border:2px" >→</mo>
            <mo>+</mo>
            <mi>y</mi>
          </mrow>
        </mover>
		
    <mspace linebreak="newline" indentalign="center"></mspace>
        <mover  style="border:1px">
          <mrow  style="border:5px">
            <mi>very long</mi>
            <mo>+</mo>
            <mo>...</mo>
            <mo>+</mo>
            <mi>texttttttttttttt</mi>
          </mrow>
          <mrow  style="border:1px">
			  <mrow  style="border:1px">
				<mi>x</mi>
				<mo>+</mo>
				<mo style="border:2px" >→</mo>
				<mo>+</mo>
				<mo style="border:2px" stretchy="false">→</mo>
				<mo>+</mo>
				<mo style="border:2px" >→</mo>
				<mo>+</mo>
				<mi>y</mi>
			  </mrow>
		  </mrow>
        </mover>
		
</math>