What are Armstrong's Axioms?

Armstrong's Axioms:

1. - Axiom of reflexivity

2. - Axiom of augmentation

3. - Axiom of transitivity

From these three axioms, the following are derived:

- Proyectivity or union

- Additivity or decomposition

- Pseudotransitivity

Explanation:

Be X, Y, W, Z are sets, then

1. - Axiom of reflexivity : ∀ Y ⊆ X ⇒ X → Y

2. - Axiom of augmentation : X →Y ⇒ ZX → ZY

3. - Axiom of transitivity: X → Y and Y → Z ⇒ X → Z

- Proyectivity or union: X → Y and X → Z ⇒ X → YZ

- Additivity or decomposition: X → Y and Z ⊆ Y ⇒ X → Z

- Pseudotransitivity: X → Y and WY → Z ⇒ WX → Z