Handling very long strings -- the string should break across a row if needed.
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <mrow> <mi>x</mi> <mo>+</mo> <mi>x</mi> <mo>+</mo> <mi>x</mi> <mo>+</mo> <ms>asdffffffasdddfaaaaaaaasssdddfaaaaaaaassdfasdffffffasdddfaaaaaaaasssdddfaaaaaaaassdf</ms> <mo>+</mo> <mn>2</mn> <mo>+</mo> <mn>2</mn> <mo>+</mo> <mn>2</mn> </mrow> </math>
Author: Design Science, Inc. (D. Doyle, R.Miner)