What schools have players that tried out for goalies?
select cname from tryout where ppos = 'goalie'
What schools have players that tried out for the mid position?
select cname from tryout where ppos = 'mid'
In which states are the schools that fit into the latter category but not the former?
select t1.state from college as t1 join tryout as t2 on t1.cname = t2.cname where t2.ppos = 'mid' except select t1.state from college as t1 join tryout as t2 on t1.cname = t2.cname where t2.ppos = 'goalie'