How many rules does Dr. E. F. Codd provide which qualify a database as a RDBMS?

Rule 0: The Foundation Rule

Rule 1: The Information Rule

Rule 2: The Guaranteed Access Rule

Rule 3: Systematic Treatment of NULL Values

Rule 4: Active Online Catalog Rule

Rule 5: The Comprehensive Data Sublanguage Rule

Rule 6: The View Updating Rule

Rule 7: High-level Insert, Update, and Delete

Rule 8: Physical Data Independence

Rule 9: Logical Data Independence 

Rule 10: Integrity Independence

Rule 11: Distribution Independence

Rule 12: Non-Subversion Rule