Subject: Re: [lojban] A or B, depending on C, and related issues

From: "Bob LeChevalier (lojbab)" <[email-masked]>
Date: Fri, 10 Aug 2001 17:43:54 -0400

At 07:52 PM 8/9/01 -0400, you wrote:
>In a message dated 8/9/2001 4:01:41 PM Central Daylight Time,
>[email-masked] writes:
>
>
>>Actually it did. lu'a for selecting individuals from a set came *directly*
>>from your posing this problem to me back in 1989 or so. The other members
>>of lu'a were added later. I believe that Athelstan then demonstrated that
>>we could match all 3 and 4 place truth functional connective truth table
>>with no obvious limit to what we could handle in larger sizes being
>>found. The form translated as "1 from the set {coffee, tea} AND 1 from the
>>set {sugar, cream} is an example of this solution. sumti sets can include
>>sets of propositions by using du'u or la'elu/li'u, which I think solves the
>>first problem.
>
>Yes, but the language uses were never written up (unless in a short bit in
>the newsletter) and are not in the Book. There are no specimens that I can
>find anywhere

I had to look a little in the archive, but found one:
http://balance.wiw.org/~jkominek/lojban/9201/msg00081.html

from Colin Fine:
>"gi'onai" etc. I've often been unhappy about the spurious precision of
>people using ".onai" rather than ".a", and this time I'm sure of it. (I
>remember a remark - possibly pc in an old The Loglanist - doubting
>whether it was true that natural language "or" is usually exclusive). If
>you draw up the truth-table for "x1 .onai x2 .onai x3" you will find
>it's true precisely when an odd number of the x's are true, and false
>when (for example) just two of them are true!. (Further, it is identical
>with "x1 .o x2 .o x3"!) I would certainly choose "gi'a" here, but if you
>want something more precise, I fear you are stuck with "palu'alu'e x1 ce
>x2 ce x3" (if I've got the right cmavo.)

> and Athelstan's proof even is lost from the material I have -- can you 
> resurrect it?

Not likely. I've established that this was already in the language in 
October 88 (per the cmavo list of that month), with a note explicitly 
referring to "the multiple connectives question", which is pretty much as 
far back as I have on-line archives (there are scattered older documents, 
but relatively little was done on a computer before then). I suspect that 
the work was done in the summer of '88 then, possibly when you were here 
for LogFest that year (June?). I recall a snail mail letter from you 
saying that you had been working on the truth tables of multiple 
connections and found that so many out of so many possibilities could not 
be covered with the existing Lojban connectives. I believe lu'i had 
already been put in the language to allow set memberships to be enumerated 
so that using set selection to solve the connectives question was a 
serendipity effect of something we put in the language for a different reason.

> It is easy to see how the "exactly n" cases work, but
>what about more complex ones that lay out interrelationships among what
>occurs or does not?

I'd need to see an example to even understand the question.

lojbab
--
lojbab [email-masked]
Bob LeChevalier, President, The Logical Language Group, Inc.
2904 Beau Lane, Fairfax VA 22031-1303 USA 703-385-0273
Artificial language Loglan/Lojban: http://www.lojban.org