Syntax::bktmcp: 
   Expression "RowBox[{{, Cell[BoxData[FormBox[GridBox[{{Cell[TextData[
               { , Cell[1, InlineFormula],  }]], 
             Cell[TextData[{ , Cell[BoxData[ if 0 ∈ A], InlineFormula], 

                 }]]}, {<
<2>>}}], TraditionalForm]]]}]" has no closing "}".

ToExpression::esntx: 
   Could not parse  \mu (A)= \begin{cases} 1 & \mbox{ if } 0 \in A \\ 
                                                  0 & \mbox{ if } 0 \notin A.
                   \end{cases}
     as input.

  <math 
    xmlns='http://www.w3.org/1998/Math/MathML'>
    <semantics>
      <mi>$Failed</mi>
      <annotation-xml encoding='MathML-Content'>
        <ci>$Failed</ci>
      </annotation-xml>
    </semantics>
  </math>