I wrote: (01)
> So in our ontology there needs to be a way to say that "these units
> belong to the same family" (inches, feet, meters, ...) or (radians,
> angular degrees, ...) and "these do not" (energy, torque). I don't
> think calling them dimensions is going to work because the term is so
> heavily overloaded. (02)
Joe Collins wrote: (03)
> To be consistent with SI nomenclature, I urge you to use the concept
> of "kind". (04)
and then later quoted the ISO standard: (05)
> Quantities of the same kind within a given system of quantities
> have the same quantity dimension. However, quantities of the same
> dimension are not necessarily of the same kind. (06)
So replace the word 'family' with 'kind', and to be more consistent with
that document, replace what I called a 'decorated value' with 'quantity'. (07)
A quantity is thing that is a value from the set of non-negative
real numbers bound together with a unit. (08)
And then: (09)
Two quantities are the same kind if there is exists a bijective
function that allows quantities in one unit to be mapped into
quantities in the other. (010)
And apparently this statement appears in multiple standards: (011)
> The division of the concept ‘quantity’ into several kinds is to some
> extent arbitrary. (012)
But I think we can reach a consensus around a list that is a little more
succinct than the examples listed, and still provide some flexibility
where 'torque' is not 'energy'. (013)
Joel (014)
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