From dpt@abel.MATH.HARVARD.EDU Sat Mar 6 22:44:54 2010 Date: Sat, 27 May 1995 17:05:13 -0400 From: "Dylan P. Thurston" Subject: Re: A Fuzzy Ship from Theseus To: Bob LeChevalier X-From-Space-Date: X-From-Space-Address: LOJBAN%CUVMB.BITNET@uga.cc.uga.edu Message-ID: <_-nyJRyko_I.A.UjE.mt0kLB@chain.digitalkingdom.org> ucleaar@ucl.ac.uk writes: > ... > 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. Hum. The reason {lo ni gusni} is bounded on one end is a absolute minimum to the amount of brightness: total darkness, while the absolute maximum is far beyond our experience. (At a certain point the energy density of the photons would create a black hole, I believe.) But this is particular to {gusni}. Is {lo jei broda} equivalent to {lo ni lodu'u broda cu fatci}? Would {ka} be more appropriate? Is the difference that truth values are usually quite near one end of the scale? > ... > 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. Excellent point. Aren't {traji}, {banli}, {mutce}, {nutli}, and {milxe} just what's wanted? (Gismu queries here: what's the relation of {carmi} and {denmi} to {mutce}? Do they just have an indication of what kind of property is expected? Why does {mutce} have a place for "in direction", while, e.g., {milxe} doesn't? Doesn't the property (the x2 place) imply the direction?) > 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. I notice you conveniently left out the ostrich... I agree the example is weak, but there is a little fuzziness here, too. For a more striking example, is the platypus a mammal? > ... > This is not necessarily the standard view, but at any rate it's what I > teach my students. Wow, do we have a live professor on the list? You teach logic, I take it? mu'o mi'e. dilyn.