Sets and Cantor

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Across
  1. 1. a set with only 1 element
  2. 4. diagram which shows a set graphically
  3. 5. marked by the character '-'
  4. 6. the theory that cantor discovered
  5. 7. marked by the character 'U'
Down
  1. 2. marked by the character '∩'
  2. 3. the country cantor belonged to
  3. 8. a set with nothing in it