<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<semantics>
<mi>τ</mi>
<annotation-xml encoding="MathML-Content">
<ci>τ</ci>
</annotation-xml>
<annotation encoding="SnuggleTeX">\[ \tau \]</annotation>
<annotation encoding="LaTeX">\[ \tau \]</annotation>
<annotation encoding="Maxima">%tau</annotation>
</semantics>
</math>
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<semantics>
<mi>τ</mi>
<annotation encoding="SnuggleTeX">\[ \tau \]</annotation>
</semantics>
</math>
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<mi>τ</mi>
</math>
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<ci>τ</ci>
</math>