anchor.diff:  process,
   message,
   takfp,
  -nsieve
  +nsieve,
   nsievebits
   fannkuch
   pidigits
  
positive.code: spectralnorm
  health
  raytracer
  binarytrees,
  implicitode,
  dispatch,
  
  
negative.code: wc,count-words
  heapsort,heapsort
  methcall,methods
  random,random
  regexmatch,regex
  spellcheck,spellcheck
  