mml=<math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mrow><msup><mfenced separators="|"><mrow><mi mathvariant="normal">l</mi><mo>+</mo><mi mathvariant="normal">b</mi><mo>+</mo><mi mathvariant="normal">h</mi></mrow></mfenced><mn>2</mn></msup><mo>-</mo><mi mathvariant="normal">&#xA0;</mi><mfenced separators="|"><mrow><msup><mi mathvariant="normal">l</mi><mn>2</mn></msup><mo>+</mo><msup><mi mathvariant="normal">b</mi><mn>2</mn></msup><mo>+</mo><msup><mi mathvariant="normal">h</mi><mn>2</mn></msup></mrow></mfenced></mrow><mn>2</mn></mfrac></math>