The ?spatdim dimensional zero vector of physical dimension ?physdim.
(Nth-Domain The-Zero-Vector-Of-Type 2 Physical-Dimension)
(Nth-Domain The-Zero-Vector-Of-Type 1 Positive-Integer)
(Nth-Domain The-Zero-Vector-Of-Type 3 Vector-Quantity)
(=> (The-Zero-Vector-Of-Type ?Spatdim ?Physdim ?V0)
(Forall (?V)
(=> (Vector-Quantity ?V)
(= (Dot ?V ?V0)
(The-Zero-Scalar-For-Dimension ?Physdim)))))