Meta Puzzle

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Across
  1. 4. A player of crossword puzzles.
  2. 6. father of the modern crossword puzzle.
  3. 7. An ancient mathematical format from which many word puzzles were born.
Down
  1. 1. _____ million Americans regularly do crossword puzzles.
  2. 2. A Crossword Puzzle _________ contains hundreds of thousands of answers and clues.
  3. 3. Author of many holiday crossword themed murder mysteries.
  4. 5. Related to and often mistaken for a true crossword puzzle. You are playing one now!