Logical notation

Just to remember, here are the most used notation in logical writting (mostly used for integrity rules definition).

ε : belongs

⊆ : is include in

∪ : union

∩ : intersection

– : is different

∅ : is empty

∧ : and

∨ : or

¬ : is not

∀ : for all

∃ : it exist

≡ : strickly egal to

× : cartesian product

|: such as

{} : ensemble

⇒ : imply

I hope it help.