Scalar-Quantities are partitioned into classes of uniform dimension. All instances of one of these classes have the same physical dimension. Each of these classes form a linear order with respect to the < relation. Length scalars, time scalars, and mass scalars are examples of scalar subclasses.
(=> (Scalar-Quantities-Of-Dimension ?Dimension ?Class)
(And (Physical-Dimension ?Dimension)
(= ?Class
(Kappa (?Q)
(And (Scalar-Quantity ?Q)
(= (Quantity.Dimension ?Q) ?Dimension))))
(Linear-Order ?Class <)))