>
  <!-- middle owned by containing block: simple -->
  <p>AAA BBB</p>
  <p>A A AB B B</p>
  <!-- middle owned by containing block: double nesting -->
  <p>AAAB B B</p>
  <p>A A AB B B</p>
  <!-- middle owned by inline: simple -->
  <p>AAA BBB</p>
  <p>A A AB B B</p>
  <!-- middle owned by inline: double nesting -->
  <p>AAAB B B</p>
  <p>A A A   B B B</p>
  <!-- middle containing space -->
  <p>AAA   BBB</p>
  <p>AAA     B B B</p>
</div>
