資料庫: Armstrongs Axioms

https://youtu.be/j4GfUYdampo

reference : https://en.wikipedia.org/wiki/Armstrong%27s_axioms

Y \subseteq X

then

X \to Y

X \to Y

, then

X Z \to Y Z

for any

Z

X \to Y

and

Y \to Z

, then

X \to Z

Additional rules
These rules can be derived from above axioms.

X \to Y

and

X \to Z

then

X \to YZ

X \to YZ

then

X \to Y

and

X \to Z

X \to Y

and

YZ \to W

then

XZ\to W