Re: [lojban] Re: except the cat

[Robin Lee Powell <rlpowell@csclub.uwaterloo.ca>]

"=?iso-8859-1?q?Alfred_W._Tueting_(T=FCting)?=" writes:
>--- In lojban@egroups.com, Pierre Abbat <phma@o...> wrote:
>> Finally figured it out:
>> 
>> roda ku'anai le mlatu
>
>I'm not at all sure about that:
>1) {ku'a} needs arguments of type "set" - "le mlatu" isn't a set, nor
>is "roda"

So use le'i.

>2) {ku'a} designates the "intersection" of different sets: how can
>"roda" have an intersection with "another" set, since *including* 
>all types of sets?

I don't think you're clear on what intersection is.  The intersection of
the total set ("roda") and any other set A is just the set A.  The point
is merely emphasis.

>3) What has {ku'anai} the power to express just by negating an
>intersection?

A friend asked that question said he would expect it to return all the
points where the two sets are not equal, which is _exactly_ the desired
result. IOW, a set XOR.

I think that it's a _WONDERFULLY_ elegant solution.

<research>

Unfortunately, this is _NOT_ the interpretation of nai for non logical
connectives specified by the book:

The following ``nai'', if present, does not negate either of the things
to be connected, but instead specifies that some other connection
(logical or non-logical) is applicable: it is a scalar negation: 

This is _VERY_BAD_, because it means that lojabn _does_not_ have a
complete set of set operators.  Union, intersection, and cartesion
product are not enough, difference is required.   In porticular, there
is _on_way_ to perform a set XOR with solely those three operations.
You need either a difference operator or a complement operator, which is
what I was treating the nai as.

Perhaps "le'i mlatu nai" could be treated as the complement of the set
containing the cat?

-Robin

-- 
http://www.csclub.uwaterloo.ca/~rlpowell/ 	BTW, I'm male, honest.
Despite not getting very emotional about it, the fact that quantum
entanglement doesn't allow transmission of information is probably the
most profound dissapointment I've ever experienced.  -- RLPowell