**Defined in theory: Scalar-quantities****Source code: scalar-quantities.lisp**

**Documentation:**A scalar-quantity is a constant quantity whose magnitude is a real number. An important property of scalar-quantities is that they form a field with respect to the addition and multiplication (with proper subclass restrictions). The class of scalar-quantities forms a partial order with the less-than relation

*<*, since*<*is a relation-extended-to-quantities and*<*is defined over the reals. The*<*relation is not a total order over the class of scalar-quantity

since elements from some subclasses such as length quantities are incomparable to elements from other subclasses such as mass quantities.**Subclass-Of:**Constant-quantity**Partial-Order:**<**Superclass-Of:**Real-number

(<=> (Scalar-Quantity ?Q) (And (Constant-Quantity ?Q) (Forall (?U) (=> (And (Unit-Of-Measure ?U) (Compatible-Quantities ?U ?Q)) (Real-Number (Magnitude ?Q ?U))))))