Question: Find the first names of professors who are not playing Canoeing or Kayaking.
SQL: SELECT lname FROM faculty WHERE rank = 'Professor' EXCEPT SELECT DISTINCT T1.lname FROM Faculty AS T1 JOIN Faculty_participates_in AS T2 ON T1.facID = T2.facID JOIN activity AS T3 ON T2.actid = T2.actid WHERE T3.activity_name = 'Canoeing' OR T3.activity_name = 'Kayaking'