anchor.diff:  acquire-lock,2
   add1,2
   alias,2
  -and,2
  +and,5
   andmap,2
   angle,2
   annotation-expression,2
  
positive.code: library-object-filename,2
  library-requirements,2
  library-version,2
  list,2
  list*,2
  list->fxvector,2
  list->string,2
  
negative.code: open-source-file,2
  open-string-input-port,2
  open-string-output-port,2
  or,4
  ormap,2
  output-port-buffer-mode,2
  output-port?,2
  