สำหรับ ELI 512 สอนโดย Prof. William Gehring หรือ Prof. Peter Yaman เสมอ ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
For ELI 512 , is it always taught by either Prof. William Gehring or Prof. Peter Yaman ?It is not neccessary to use all the tables.
 program:  program_id [ int]  name [ varchar]  college [ varchar]  introduction [ varchar] 
SELECT COUNT(*) = 0 FROM course, course_offering, instructor, offering_instructor WHERE (NOT instructor.name LIKE '%William Gehring%' AND NOT instructor.name LIKE '%Peter Yaman%') AND course.course_id = course_offering.course_id AND course.department = 'ELI' AND course.number = 512 AND offering_instructor.instructor_id = instructor.instructor_id AND offering_instructor.offering_id = course_offering.offering_id