Subject: Re: [lojban] tautologies

From: [email-masked]
Date: Tue, 12 Feb 2002 10:00:24 EST

In a message dated 2/11/2002 6:45:01 PM Central Standard Time, 
[email-masked] writes:

> > These all have the same truth values, but are otherwise only incidentally
> >related to one another.
> 
> But are the connectives about anything else other than truth
> values? What is this additional relationship that exists between
> {je naku} and {jenai} but is absent in other combinations that
> provide the same truth table? Is the equivalence between
> {najo} and {jonai} of the interesting type, or just the same
> truth value type?

Well, it is clear that {jenai} is, as it were, *defined* as {je naku}, while 
{ju} is not defined at all within the system, and, if it were, would be 
define by simply leaving out what followed: p iju q <=> p. XORs various forms 
are truth functional only, in this sense.

<. In one case, you have a differnt 
>thing
>satisfying the sense of what is said, in the other you have a different 
>sense
>altogether.

Yes, I agree that there are differences, although I'm not too
clear on what exactly they are or what follows from them.>

Given that a tautology is a proposition that is always true, qkau, since it 
changes the proposition, is not a tautology. Note: this goes back to an 
earlier position of mine and so may no longer be the main thrust of my 
complaint.

<>It is when you say things like the above that I feel justified
>in thinking that you still are drawn to the notion that the answer to a
>question is just what fills the gap, rather than the whole sentence that
>answers it.

I was never drawn to that notion, so I will protest the "still".>

So you have been saying for several years, but each time in answer to my 
comments about something you say that makes sense (if at all) only in 
connection with the view that answers are what fill the gaps-- the instant 
case being an example.

<>Put another way, {ta} is not {le ladru}, though it may happen to refer to 
>le
>ladru, to a particular bit of milk. But {ta se jdima makau} really is {ta 
>se
>jdima - 50 cents} or whatever the case may be -- even if you don't know 
>what
>proposition you are committing to, but you do know it is true.

I don't understand why {ta} is not {le ladru}. Isn't
{ta du le ladru} true? Of course the word "ta" is not the milk
it refers to, but then neither are the words "ta se jdima makau"
the proposition they refer to.>

Partly, {ta} is not {la ladru} because it is clearly another word; you have 
made a use-mention error here. {ta} refers to la ladru or to the same thing 
{la ladru} does, and so {ta du la ladru} is true, but {zo ta du li la ladru 
li'u} is not. Also, of course, {ta se jdima makau} doesn't refer to a 
proposition but to either a state of affairs or a truth value. 
But that is all technical argle-bargle: the main point is that, although the 
reference of {ta} may change in {mi vecnu ta}, say, (and of {mi}, too, for 
that matter), the proposition remains the same (roughly "the speaker 
purchases the near object to which attention is directed") , while with 
{makau} in {ta se jdima makau} the whole proposition changes with what fits 
the {makau}, one time fifty cents, another time a dollar and so on. {makau} 
is not a referring expression, and what replaces it is a specific (in your 
intended meaning), not a mere indexical, whose referent can shift with 
context.