**Arity:**2**Domain:**Quantity-function**Range:**Class**Subrelation-Of:**Total-on

(<=> (Quantity-Function-Total-On ?Quantity-Function ?Class) (And (Quantity-Function ?Quantity-Function) (Class ?Class) (Total-On ?Quantity-Function ?Class)))

**Formerly-Called:**quantity-function-of- This used to be defined as the INVERSE relation of has-quantity-function. But now, has-quantity-function is defined as an instance-slot (i.e., its domain is instances of a class), so the inverse quantity-function-of would only point at instances.