<math display='block'> <mml:mrow> <mml:mi>T</m:mi><mml:mo>=</m:mo><mml:mo stretchy='false'>(</m:mo><mml:mn>1</m:mn><mml:mo>+</m:mo><mml:mfrac> <mml:mn>1</m:mn> <mml:mi>m</m:mi> </m:mfrac> <mml:mo stretchy='false'>)</m:mo><mml:mi>B</m:mi><mml:mo>+</m:mo><mml:mi>W</m:mi> </m:math>