SELECT T1.emp_fname FROM employee AS T1 JOIN CLASS AS T2 ON T1.emp_num  =  T2.prof_num WHERE crs_code  =  'CIS-220' INTERSECT SELECT T1.emp_fname FROM employee AS T1 JOIN CLASS AS T2 ON T1.emp_num  =  T2.prof_num WHERE crs_code  =  'QM-261'
What is the first name of the professor who is teaching CIS-220 and QM-261?
SELECT T1.emp_fname FROM employee AS T1 JOIN CLASS AS T2 ON T1.emp_num = T2.prof_num WHERE crs_code = 'CIS-220 ' INTERSECT SELECT T1.emp_fname FROM employee AS T1 JOIN CLASS AS T2 ON T1.emp_num = T2.prof_num WHERE crs_code = 'QM-261 '
select t1 . emp_fname from employee as t1 join class as t2 on t1 . emp_num = t2 . prof_num where crs_code = value intersect select t1 . emp_fname from employee as t1 join class as t2 on t1 . emp_num = t2 . prof_num where crs_code = value
What is the first name of the professor who is teaching CIS-220 and QM-261 ?