Third Normal Form

Third Normal Form (3NF) defines a relation $$R$$ and functional dependencies $$F$$ complies if for all $$X \rightarrow A$$ in $$F^+$$ If a relation is in Boyce-Codd Normal Form, then it is in Third Normal Form already.
 * $$A \in X$$ (trivial functional dependency), or
 * $$X$$ is a superkey of $$R$$, or
 * $$A$$ is part of some candidate key (not superkey!) for $$R$$

Lossness
A lossness join decomposition is always possible with Third Normal Form

Dependency Preservation
A dependency preserving decomposition is always possible with Third Normal Form