GoodBreak test
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <mi>B</mi>
  <mo>-</mo>
  <mi>B</mi>
  <mo>-</mo>
  <mi>B</mi>
  <mo>-</mo>
  <mspace linebreak="goodbreak"/>
  <mi>a</mi>
  <mo>-</mo>
  <mi>a</mi>
  <mo>-</mo>
  <mi>a</mi>
  <mo>-</mo>
  <mi>a</mi>
</math>
Author: Design Science, Inc. (D. Doyle, E. Cannon, E. Tabacman, R.Miner)