Geometry puzzle

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Across
  1. 3. based on evidence
  2. 9. table of truth values
  3. 10. uses deductive reasoning
  4. 11. line intersects
  5. 13. unproven statement
  6. 14. boxes/arrows
  7. 17. if p, then q
  8. 20. if and only if
  9. 21. if p, then q
  10. 22. if
Down
  1. 1. flipped
  2. 2. "not"
  3. 4. based on patterns
  4. 5. negated and flipped
  5. 6. proves false
  6. 7. intersect - right angle
  7. 8. negate both sides
  8. 10. paragraph
  9. 12. both true/false
  10. 15. true or false
  11. 16. statement that can be proven
  12. 18. numbered statements
  13. 19. then