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)
(Forall (?Physdim ?Spatdim) (Abelian-Group (Vector-Quantities-Of-Dimensions ?Physdim ?Spatdim) + (The-Zero-Vector-Of-Type ?Spatdim ?Physdim))) (=> (And (Vector-Quantity ?X) (- ?X ?Y)) (And (Vector-Quantity ?Y) (= (+ ?X ?Y) (The-Zero-Vector-Of-Type (Quantity.Dimension ?X) (Spatial.Dimension ?X))))) (=> (= (The-Zero-Vector-Of-Type ?Spatdim ?Physdim) ?V0) (Forall (?V) (=> (Vector-Quantity ?V) (= (Dot ?V ?V0) (The-Zero-Scalar-For-Dimension ?Physdim)))))