CREATE TABLE acceptance (submission_id DECIMAL, workshop_id DECIMAL, result TEXT)
CREATE TABLE submission (submission_id DECIMAL, scores DECIMAL, author TEXT, college TEXT)
CREATE TABLE workshop (workshop_id DECIMAL, date TEXT, venue TEXT, name TEXT)

List the authors who do not have submission to any workshop.
SELECT author FROM submission WHERE NOT submission_id IN (SELECT submission_id FROM acceptance)
SELECT "author" FROM "submission" WHERE NOT "submission_id" IN (SELECT "submission_id" FROM "acceptance")