Search:

Forall x . P(x) <=> not (Exists x . not P(x))

meaning that any x (in some unspecified set) has property P which is equivalent to saying that there does not exist any x which does not have the property.

If a variable is not quantified then it is a free variable. In logic programming this usually means that it is actually universally quantified.

See also first order logic.

(2002-05-21)

© Art Branch Inc.

SQL Tutorial