Plurals, sets, masses, sequences -- decisions on the weekend

[John Cowan <cbmvax!UUNET.UU.NET!snark.thyrsus.com!cowan>]

la lojbab. has asked me to write up what was decided during my visit to
Lojban Central on these issues.

One of the aims of the place structure review was to examine all the place
structures that were labeled "(plural/set)" to see whether an actual set
was wanted, or merely one or more individuals.  In addition, sometimes a
mass seemed to be the right thing.  The new place structures which lojbab
is typing up will contain a good deal of clarification.

Essentially, a true set is required if the relationship does not hold of
each member but only of the totality.  For example, "kampu", "cnano", and
"fadni" are all relationships between a set and one of its members
(or a property thereof).  If I am typical of the set of persons, that
does not mean that the relation "typical-of" holds between me and every
individual person -- indeed, the idea of one person being typical of another
makes no sense.

On the other hand, we decided that "casnu" should have a mass, rather than
either a set or plural individuals, in its x1 place.  People may "casnu",
or participate in a discussion, even though not all of them say anything.

In many cases, "(plural/set)" came up where "between" or "among" was involved.
Most of these we tried to reword to avoid the problem, which often resulted
from excess generality.  Thus a wall now separates exactly two things, and
a door connects exactly two.  (A wall may separate multiple pairs of things --
my house from yours, my property from yours, Country 1 from Country 2 --
all at once, but the relationship is still pairwise.)

In addition, the phrase "ordered set" was changed throughout to "sequence", and
the place structure of "porsi" is now something like "x1 is a sequence of
the members of set x2 ordered by rules x3".  Sequences do not have the same
level of support in Lojban as individuals, masses, and sets; however, we have
long had the non-logical connective "ce'o" which constructs them item by
item.  In addition, we added "vu'i", a converter of selma'o LUhI, transforming
a set into a sequence, as well as individuals into a sequence-in-extension.

It now seems that "fa'u", the non-logical connective for "respectively", may
be taken to generate a sequence-in-extension, thus:

        mi fa'u do se cmene la djan. fa'u la lojbab.
        I respectively-with you is-benamed John respectively-with Lojbab.

Using ".e" connection will not do, as that means that each of us is named both
John and Lojbab.

--
cowan@snark.thyrsus.com         ...!uunet!cbmvax!snark!cowan
                e'osai ko sarji la lojban