query: SELECT lname FROM student WHERE sex  =  'F' AND city_code  =  'BAL' UNION SELECT lname FROM student WHERE sex  =  'M' AND age  <  20
question: What-all is the last name of every student which is either female or a-living in a city with the code BAL or male and under 20?
query_toks: SELECT lname FROM student WHERE sex = 'F ' AND city_code = 'BAL ' UNION SELECT lname FROM student WHERE sex = 'M ' AND age < 20
query_toks_no_value: select lname from student where sex = value and city_code = value union select lname from student where sex = value and age < value
question_toks: What-all is the last name of every student which is either female or a-living in a city with the code BAL or male and under 20?