TECH: Lujvo Place structure paper

[Nick Nicholas <nsn@MULLIAN.EE.MU.OZ.AU>]

This is the introduction to a lujvo place structure paper, which I offer
to the list for comments.

***

1. Introduction

Tanru in Lojban are a combination of two or more predicates. Since each
predicate expresses a relation between its arguments, tanru express a
relation between the arguments of all its components. Take for example
the tanru {gerku zdani}. {gerku} expresses a relation between an individual
dog {le gerku}, and a dog breed {le se gerku}. {zdani} expresses a relation
between a house {le zdani}, and someone housed {le se zdani}. The tanru
{gerku zdani}, which denotes something to do with both dogs and houses,
expressed a relationship between the dog, its breed, the house, and the
house occupant. This relationship is inherently ambiguous, but all these
places can be made explicit. If we want to somehow relate Spot, a Saint
Bernard, with the White House, home of the U.S. President, we *can* speak
of:

la blabyzdan. cu gerku befa la spat. bei la sanktbernard. be'o zdani le
merli'e --- [1.1]

Of course, a tanru is not the same as a simple gismu: not all the sumti
need be present, and not all of them need have the same interpretation
as they do in the original gismu. One of the possible interpretations
of {gerku zdani} is dog kennel. Obviously, if we're talking dog kennels,
we are expressing a relation between a dog and a house; it is not as clear
that we are also expressing a relation involving a dog breed, or a
resident of the house *distinct* from the dog. If we are to speak of
Spot's kennel, called Mon Repos, we may say:

la monrePOS. cu gerku befa la spat. bei la sanktbernard. be'o zdani la
spat. --- [1.2]

But obviously {le gerku} is the same as {le se zdani}, so we lose no
precision by saying:

la monrePOS. cu gerku bei la sanktbernard. be'o zdani la spat. --- [1.3]

Furthermore, it *can* be argued that a kennel is a kennel, regardless of
what breed of dog lives in it, that the breed is not important to the
*definition* of a kennel, and that only such important arguments should
be present in a bridi. If we accept this argument, then the fact that Spot
is a St Bernard does not add any important information to the claim that
Mon Repos is his kennel. Thus there are only two important sumti left:

la monrePOS. cu gerku zdani la spat. --- [1.4]

A lujvo is equivalent to a tanru, but it unambiguously expresses a specific
chosen relation out of the many an ambiguous tanru can convey. As distinct
from a tanru, it does not nest its sumti: all its component sumti appear
in sequence, as they do for a gismu. Compare:

.i (mi) zmadu (do) {leka (mi) barda (leka xadycla kei) (lo'e remna) kei}
(pimu mitre) --- [1.5]

.i (mi) barda {be (leka xadycla kei) bei (lo'e remna) be'o} zmadu (do)
(zo'e) (pimu mitre) --- [1.6]

.i (mi) badmau (do) (leka xadycla kei) (lo'e remna) (pimu mitre) --- [1.7]

I exceed you in height, by normal human standards, by half a metre.

The place structure of a lujvo is extremely important. In Lojban, as a
predicate language, place structure is essential to the *definition* of
a word, whether gismu or lujvo. As we saw with the {gerku zdani} example,
not all the places of the component gismu will be as important in this
definition. Some may be omitted altogether in the lujvo place structure;
some may be merged with other places, and some may have their meaning
shift. The ability to select amongst the places of the original gismu
those that are to go into the final lujvo is critical to making lujvo that
clearly and succinctly express the relation desired.

An important issue with using selbri in Lojban is remembering the right
order of the sumti. This becomes critical with lujvo: the set of places
selected must be ordered in such a way, that the user who is unfamiliar
with the lujvo be able to tell and remember which place is which. The
ordering of places should therefore somehow be reproducible, and follow
some consistent pattern.

Good place selection thus ensures that the lujvo meaning is clearly and
economically expressed. Good place ordering ensures that the lujvo is
reproducable and intelligible without needing to rely on context. Neither
principle is absolute: there are cases in which they need to be violated
to accomodate the meaning of the lujvo better. In general it is desirable
to adhere to them, but we must remember that these are guidelines only.
They cannot be expressed as rigid rules. Lujvo place structures are too
complex an issue to admit that level of detail, or any official edict
dictating their formation. This is why this chapter does not have the same
force as other sections of the dictionary, and does not represent official
LLG policy. None the less, they deserve attention. If a desired place
structure does not match that obtained by these guidelines, the base tanru
chosen to express the desired concept may not be the best for the job,
and may not be expressing what you actually intend it to. Generally, there
should be no need to introduce places external to the component gismu,
or to radically reorder the lujvo places, though this cannot be ruled out.



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non me tenent vincula, non me tenet clavis, % (nsn@munagin.ee.mu.oz.au)
quaero mei similes et adjungor pravis.      % Nick Nicholas, striver, EE&CS,
      --- Archipoeta, _Confessio_.          % Univ. of Melbourne, Australia