Metrology and exact/approximate numbers

[John Cowan <cbmvax!snark.thyrsus.com!cowan>]

Earlier this month there was much talk about whether 0.9 is equal to 9/10
or not, and what the significance of Lojban numbers is when measurements
are involved.  Here's my current position on the matter, on which I solicit
comments:

9/10 (sofi'upano) has the same value as .9 (piso), because both are exact
numbers.  We do have the cmavo "ji'i", which has the same grammar as a digit,
and is used to indicate approximation.  Current examples are

	ji'i vo no
	approximately four zero
	about forty

	re pi ze re ji'u ma'u
	two point seven two approximately positive-sign
	2.72 (rounded up)

	re pi ze pa ji'i ni'u
	two point seven one approximately negative-sign
	2.71 (rounded down)

Based on these examples, it seems to me that if we want to say "3.1418" and
indicate that the last digit is an approximation (in other words, our
measurements are only accurate to .001 precision), we can say:

	ci pi pa vo pa ji'i bi
	three point one four one approximately eight

Comments?

--
cowan@snark.thyrsus.com		...!uunet!cbmvax!snark!cowan
		e'osai ko sarji la lojban