<Li> Reflexivity: If Y is a subset of X, then X → Y </Li> <Li> Augmentation: If X → Y, then XZ → YZ </Li> <Li> Transitivity: If X → Y and Y → Z, then X → Z </Li> <P> "Reflexivity" can be weakened to just X → ∅ (\ displaystyle X \ rightarrow \ varnothing), i.e. it is an actual axiom, where the other two are proper inference rules, more precisely giving rise to the following rules of syntactic consequence: </P>

Which forms are based on the concept of functional dependency