Unexpected space between text and number in \operatorname{}

Issue Summary

When rendering

\operatorname{atan2}(y,x)

using MathJax v3, a space was mistakenly inserted between “atan” and “2”.

Steps to Reproduce:

Use MathJax v3 to render:

\operatorname{atan2}(y,x)

or

\DeclareMathOperator{\atantwo}{atan2}
\atantwo(y,x)

Below is MathML produced by MathJax v3:

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <mrow data-mjx-texclass="OP">
    <mi>atan</mi>
    <mn>2</mn>
  </mrow>
  <mo stretchy="false">(</mo>
  <mi>y</mi>
  <mo>,</mo>
  <mi>x</mi>
  <mo stretchy="false">)</mo>
</math>

While MathJax v2 generates:

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <mstyle displaystyle="true" scriptlevel="0">
    <mrow class="MJX-TeXAtom-ORD">
      <mi>atan2</mi>
      <mo>&#x2061;<!-- ⁡ --></mo>
      <mo stretchy="false">(</mo>
      <mi>y</mi>
      <mo>,</mo>
      <mi>x</mi>
      <mo stretchy="false">)</mo>
    </mrow>
  </mstyle>
</math>

Technical details:

• MathJax Version: 3.2.2 (Latest, using official example)
• Client OS: macOS 13.0 (22A380)
• Browser: Safari 16.1 (18614.2.9.1.12)

Supporting information:

The result of MathJax v2 was generated by this online demo.