message: book -> bool
diff: # Find the next value `p` in `table` that's greater than
  # `currentP`, and is not marked. If there are no numbers
  # in the table left that meet those criteria, return 0.
  -@findNextP(table: ptr<book>, tableSize: int, currentP: int) : int {
  +@findNextP(table: ptr<bool>, tableSize: int, currentP: int) : int {
  zero: int = const 0;
  one: int = const 1;
  p: int = id currentP;
  