declare md$structure literally
  'structure(
  link word,
  start word,
  length word,
  plist word,
  unused word)';

declare ms$structure literally
  'structure(
   link word,
   start word,
   length word,
   flags word,
   mau word)';

declare sat$structure literally
  'structure(
   start word,
   len   word,
   num$allocs byte)';