a) The DV_QUANTITY_RATIO class should probably be generic,
i.e. have the specification DV_QUANTITY_RATIO <N->DV_QUANTIFIED,
M->DV_QUANTIFIED> - this would allow archetypes to state exactly
what kind of ratio it was (e.g. mass / volume).
b) Should it also inherit from DV_QUANTIFIED, as is done in HL7?
Have to investigate which of the arithmetic operations are
DK: Supportive of generic approach proposed for a). Not sure if
I have understood (b) correctly: a ratio to inherit from a
quantity? I thought we previously felt this was inappropriate
DK/TB: agree that b) would be incorrect - there appears to be no
argument for QUANTITY_RATIOs to inherit from QUANTITY.