CREATE TABLE scientists (ssn NUMBER, name CLOB)
CREATE TABLE projects (code CLOB, name CLOB, hours NUMBER)
CREATE TABLE assignedto (scientist NUMBER, project CLOB)

Find the name of scientists who are not assigned to any project.
SELECT name FROM scientists WHERE NOT ssn IN (SELECT scientist FROM assignedto)
SELECT "name" FROM "scientists" WHERE NOT "ssn" IN (SELECT "scientist" FROM "assignedto")