Re: A Fuzzy Ship from Theseus

[ucleaar <ucleaar@UCL.AC.UK>]

Dylan:
> > >Perhaps there is an upper limit on {lo jei c g} (e.g. a value of 1),
> > >but no upper limit on {lo ni carmi gusni} (allowing for infinite
> > >brightness). What do you reckon?
>
> I'm suspicious of making {lo jei broda} a number at all.  People don't
> tend to quantify things precisely, so assigning a number makes me
> wary.  And there's a lot more going on in natlang semantics; for
> instance, the truth of a statement is usually relative to some
> context.  Quite possibly the set of contexts that makes a statement
> true is enough to determine the "fuzziness".

The relevant distinction is the structure of the scale.  Ni is bounded
at the negative end of the scale and unbounded at the positive end of
the scale.  True/false in fuzzy logic is bounded at both ends of the
scale.  True/false, correct/incorrect in English lexical semantics is
bounded at the positive (true/correct) end of the scale and unbounded at
the negative end.  Whichever scale structure you choose for true/false,
it's different from the scale structure for ni.

Jorge:
> Fuzzy logic always comes up with regard to {jei}, but I don't
> really understand of what use it is. Besides the trivial examples
> like:
>        le jei ti blanu cu du li pibimu
>        The extent of truth of "this is blue" is 0.85
> which I suppose nobody would ever want to use, {jei} doesn't seem
> to be all that relevant to fuzzy usage.

For meanings like "ish", "sort of".  I agree {jei} doesn't really have
the right syntax to do the job.  Something in NA would be more
appropriate.

> What could be useful would be a way of assigning some truth scale to what
> is being said, not to some quoted sentence. There are (at least) two ways
> to do this. One is to use tanru with {mutce}, {traji}, etc. You can't
> ask for more fuzziness than tanru. Another way is to use attitudinals,
> for instance the scale:
> ju'ocai    absolute certainty
> ju'osai
> ju'o
> ju'oru'e   weak certainty
> ju'ocu'i   uncertainty
> ju'onai    impossibility
> Adding that to a sentence is somewhat like giving it a fuzzy truth
> value. So I can say {ju'osai ti blanu} "This is ceratinly blue",
> or {ju'oru'e ti blanu} "This is blue, I suppose".

These, I think, are epistemic, and so not what we're after.  They
indicate degrees of the speaker's confidence about whether what is
asserted is true.  Compare:

   Maybe it's bluish.
   Maybe it's 100% blue.
   It's certainly bluish.
   It's certainly 100% blue.

Steven:
 > Consider the (frequently cited) example of birds. Here is my (arbitrary)
 > list of things from most birdlike to least:
 >
 > Eagle, Pigeon, Penguin, Ostrich, Bat, Flying Squirrel, Jack Rabbit.

I believe in fuzzy categories, and I recognize that this example is from
time to time used to exemplify the notion, but I think it is not in the
least fuzzy.  Eagles, pigeons, penguins are all indubitably birds, and
bats, squirrels are indubitably not birds.  These are on a TYPICALITY
GRADIENT [emphasis, not yelling] but not a MEMBERSHIP GRADIENT.
Contrast this with the category Square:  the further something is from
having four sides of equal length and four angles of 90 degrees, the
less it is a square, but it isn't possible to say when it becomes
definitely not a square.  A category has gradient membership iff it has
defining features.

This is not necessarily the standard view, but at any rate it's what I
teach my students.

---
And