<math display="block"> <mml:mrow> <mml:munderover> <mml:mstyle mathsize='140%' displaystyle='true'><mml:mo>&#x222B;</m:mo></m:mstyle> <mml:mn>0</m:mn> <mml:mi>&#x221E;</m:mi> </m:munderover > <mml:mi>f</m:mi><mml:mo stretchy='false'>(</m:mo><mml:mi>x</m:mi><mml:mo stretchy='false'>)</m:mo><mml:mi>d</m:mi><mml:mi>x</m:mi><mml:mo>=</m:mo><mml:munderover> <mml:mstyle mathsize='140%' displaystyle='true'><mml:mo>&#x222B;</m:mo></m:mstyle> <mml:mn>0</m:mn> <mml:mi>&#x221E;</m:mi> </m:munderover > <mml:mi>f</m:mi><mml:mo stretchy='false'>(</m:mo><mml:mi>x</m:mi><mml:mo stretchy='false'>)</m:mo><mml:msup> <mml:mi>e</m:mi> <mml:mi>x</m:mi> </m:msup> <mml:msup> <mml:mi>e</m:mi> <mml:mrow> <mml:mo>&#x2212;</m:mo><mml:mi>x</m:mi> </m:mrow> </m:msup> <mml:mi>d</m:mi><mml:mi>x</m:mi><mml:mo>=</m:mo><mml:munderover> <mml:mstyle mathsize='140%' displaystyle='true'><mml:mo>&#x222B;</m:mo></m:mstyle> <mml:mn>0</m:mn> <mml:mi>&#x221E;</m:mi> </m:munderover > <mml:mi>g</m:mi><mml:mo stretchy='false'>(</m:mo><mml:mi>x</m:mi><mml:mo stretchy='false'>)</m:mo><mml:msup> <mml:mi>e</m:mi> <mml:mrow> <mml:mo>&#x2212;</m:mo><mml:mi>x</m:mi> </m:mrow> </m:msup> <mml:mi>d</m:mi><mml:mi>x</m:mi><mml:mo>=</m:mo><mml:munderover> <mml:mstyle mathsize='140%' displaystyle='true'><mml:mo>&#x2211;</m:mo></m:mstyle> <mml:mrow> <mml:mi>s</m:mi><mml:mo>=</m:mo><mml:mn>1</m:mn> </m:mrow> <mml:mi>N</m:mi> </m:munderover > <mml:msub> <mml:mi>w</m:mi> <mml:mi>s</m:mi> </m:msub> <mml:mi>g</m:mi><mml:mo stretchy='false'>(</m:mo><mml:msub> <mml:mi>x</m:mi> <mml:mi>s</m:mi> </m:msub> <mml:mo stretchy='false'>)</m:mo> </m:mrow> </m:math>