ag-gipp/GoUldI

<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>y</mi><mrow><mo rspace="0.3em" lspace="0em" stretchy="true" fence="true" form="prefix">(</mo><mi>x</mi><mo rspace="0em" lspace="0.3em" stretchy="true" fence="true" form="postfix">)</mo></mrow><mo>=</mo><mrow>\mathop<mstyle mathvariant="normal"><mi>s</mi><mi>g</mi><mi>n</mi></mstyle></mrow><mrow><mo rspace="0.3em" lspace="0em" stretchy="true" fence="true" form="prefix">(</mo>{<mi>&#x003C1;</mi>}<mo rspace="0em" lspace="0.3em" stretchy="true" fence="true" form="postfix">)</mo></mrow><mfrac linethickness="1"><mrow><mrow><msub><mi>&#x003C3;</mi><mi>y</mi></msub></mrow></mrow><mrow><mrow><msub><mi>&#x003C3;</mi><mi>x</mi></msub></mrow></mrow></mfrac><mrow><mo rspace="0.3em" lspace="0em" stretchy="true" fence="true" form="prefix">(</mo><mrow><mi>x</mi><mo>-</mo><mrow><msub><mi>&#x003BC;</mi><mi>x</mi></msub></mrow></mrow><mo rspace="0em" lspace="0.3em" stretchy="true" fence="true" form="postfix">)</mo></mrow><mo>+</mo><mrow><msub><mi>&#x003BC;</mi><mi>y</mi></msub></mrow></mrow></math>