mml=<math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">M</mi><mo> </mo><mo>+</mo><mo> </mo><mi mathvariant="normal">K</mi><mo>;</mo><menclose notation="box"><mi mathvariant="normal">T</mi><mo> </mo><mo>?</mo><mo> </mo><mi mathvariant="normal">C</mi></menclose><mo>;</mo></math>