(=> (Instance-Of ?Unit ?System)
(= (Standard-Unit ?System (Quantity.Dimension ?Unit)) ?Unit))
(<=> (System-Of-Units ?System)
(And (Class ?System)
(Subclass-Of ?System Unit-Of-Measure)
(=> (Instance-Of ?Unit ?System)
(= (Standard-Unit ?System (Quantity.Dimension ?Unit))
?Unit))
(Value-Cardinality ?System Base-Units 1)
(=> (Member ?Unit (Base-Units ?System))
(Instance-Of ?Unit ?System))
(Orthogonal-Dimension-Set
(Setofall ?Dim
(Exists (?Unit)
(And (Member ?Unit
(Base-Units ?System))
(= ?Dim
(Quantity.Dimension ?Unit))))))))
(=> (= (Standard-Unit ?System-Of-Units ?Dimension) ?Unit)
(= (Quantity.Dimension ?Unit) ?Dimension))
(=> (= (Standard-Unit ?System-Of-Units ?Dimension) ?Unit)
(Instance-Of ?Unit ?System-Of-Units))
(=> (= (Standard-Unit ?System-Of-Units ?Dimension) ?Unit)
(Unit-Of-Measure ?Unit))
(=> (= (Standard-Unit ?System-Of-Units ?Dimension) ?Unit)
(Physical-Dimension ?Dimension))
(=> (= (Standard-Unit ?System-Of-Units ?Dimension) ?Unit)
(System-Of-Units ?System-Of-Units))
(<- (Magnitude-In-System-Of-Units ?Q ?System)
(Magnitude ?Q (Standard-Unit ?System (Quantity.Dimension ?Q))))