<math  xmlns="http://www.w3.org/1998/Math/MathML" display="block" ><mrow >                                     <mi >k</mi> <mo class="MathClass-rel">=</mo><mo class="MathClass-op"> sin</mo><!--nolimits--> <mi >&#x03B1;</mi><mo class="MathClass-punc">,</mo>   <mo class="MathClass-rel">|</mo><mi >k</mi><mo class="MathClass-rel">|</mo><mo class="MathClass-rel">&#x2264;</mo> <mn>1</mn></mrow></math>