TECH: Problem - Morphology Algoirthm - Important/Urgent

[Logical Language Group <lojbab@GREBYN.COM>]

Ooops.  I may have spoken too soon.  Nora's program and morphology
algorithm is not yet available.  She just found two unresolved problems,
one probably minor and the other serious, in our rules for le'avla.

(For those who haven't been following, the proposed baseline morphology
algorithm printed in JL16 was to be tested for conformance with the
actual morphology which has long been frozen, and to make sure that
there were no unforeseen problems that would invalidate the claim that
Lojban is morphologically unambiguous.  Up till now all problems found
were in the wording of the algoirthm, which had several problems as
printed.)

Since we love to air our dirty laundry and language designs for all of
the community to appreciate (and because these problems are with a
baselined component of the language, and because we don't have an answer
to the problems ...), here's what is up.

1. First, the easy one.

Diphthongs

Lojban has 4 diphthongs permitted anywhere in the language:  ai, au, ei,
oi.  There are also some other diphthongs that occur in vowel-only
cmavo:  ia, ie, ii, io, iu, ua, ue, ui, uo, uu

It is unclear in the language definitions whether the latter are
permitted in names and in le'avla.  The former seems relatively likely
because we worded the rules rather loosely.  The latter is totally
unclear, and the wording of the algorithm depends on whether they are
included.  The i- diphthongs seem like they would be especially useful
with Lojbanizing palatalized Russian consonants in names and borrowings.

I don't think there is any problem with permitting them, but we have to
make SURE that they don't cause any problems before the book comes out.

Opinions?

2. The bad one

Our technique of making instant le'avla, by gluing an affix on the front
of most any form with a syllabic consonant, often generates words that
fail (fall apart), given the most obvious interpretation of the rather
vague wording that we used in the Synopsis that describes the morphology
baseline.  Indeed, one of the example words in the Synopsis (ricrmeiple)
falls apart.  Why?

There is nothing that keeps the "ri" from falling off, leaving the odd,
but apparently perfectly valid le'avla form "crmeiple".  Our rules on
consonant clusters are ill defined.  In one place it says that clusters
must be valid medial triples.  This means, with a few exceptions
specifically noted, that for a triple C1C2C3, C1C2 must be a valid
medial and C2C3 must be a valid initial.  No other definition of cluster
is found in the documentation, and there is thus no official statement
in print that I know of about clusters of 4 or more consonants (possible
if one or more is a syllabic l/m/n/r).

(Note that this would appear to completely invalidate "ricrmeiple" since
C2C3 is 'rm', not a permissible initial, and of course a triple that
started a name or le'avla would HAVE TO start with a permissible initial
- this is not explicitly stated in the rules for free-form le'avla.
This portion of the problem may be just a documentation error, because I
think the question has come up before about consonant clusters at both
the beginning and ends of names.)


The problem is broad, you get a CV falling off in many cases where there
is an unreduced affix of the form CVCC(r/n) glued on the front - any
time that the CC is a permissible initial pair.  e.g.

cidjrspageti

or even worse

ciskrspageti

(which DOES have the valid C2C3 called for in the rules).

The problem also occurs in ALL cases where a CVC affix ending other than
in l, n, or r is glued onto the front of a le'avla root, since you end
up with a "Cr" or "Cn" as the first cluster. e.g.

cidrspageti

With vowel initial roots, things are even worse:

Take the simple root:
okra

Any method used to attach cid(r)- or cidj(r)- or cisk(r)- is going to
have problems.

History gives us no real answers.  At the end of this message, marked by
an ***, I discuss TLI's system (for those who want to skip it).

So what can we do?

Fixes can include making far more severe constraints on initial clusters
in le'avla, probably explicitly excluding syllabic consonants.  If we
wrote the rules well enough, we can have the algorithm recognize and
distinguish syllabification caused by these consonants, even when the
imput is not marked for it (i.e., the rules don't in theory now
distinguish

"cidrspageti" with no syllabic 'r'
(which is theoretically pronouncible from
"cidr,spageti"

(a voice recognition system would probably make such a distinction, but
it becomes critical to the algorithm to note that syllable break)

Whatever we do, we need to make our definitions of permissible clusters
much more clear.  And wording those definitions to forbid clusters such
as "drs" at the beginning of a word, to prevent "cidrspageti" from
falling apart, could be high on the list.

But we have to remember that every such restriction that we put on
clusters makes le'avla space a bit smaller, and may thus mean that the
process of Lojbanizing a word for le'avla-making might get more
difficult - and less like the way of comparatively Lojbanizing the same
word into a name form (do we permit a cluster such as "spr" at the
beginning of a le'avla?)

Nora and I welcome all attempts to state rules for clusters clearly
for use in the reference book that will shortly replace the Synopsis
as the standard for Lojban, and preferably which minimize the restriction
of le'avla space.

lojbab


*** TLI system

JCB's description in NB3 is unclear on what types of clusters are
permitted in borrowings.  Presumably, he would have constrained against
the forms that cause our problems.  There is no explicit rule that makes
exceptions to the phonology rules for Loglanizing borrowings (L1
explicitly places no constraints on names other than consonant ending
and only-Loglan-phonemes - thus 'hkpth' is theoretically valid in his
system - and he has many required pauses to prevent things like "la"
from being absorbed into names (pauses that, as Jeff Prothero just noted
on conlang, JCB admits he often omits in his own Loglan speech).

The method used for making borrowings given in 4th edition L1 does not
appear to generate words that fail, but the algorithm isn't stated very
clearly, and all of the examples given are fairly straightforward
European roots, most with no impermissible Loglan clusters after the
obvious phonology changes are taken into account.

However that algorithm uses two techniques we can't or won't adopt, and
which don't work anyway to solve the problem:  TLI 'repairs' words with
no consonant cluster or with otherwise permissible initials by inserting
an 'h' after the cluster, forcing a new syllable since 'h' is not the
second letter in any permissible initial cluster

(atom -> athomi)
(asparagus -> aspharage).

Actually, JCB's rules >AS STATED< do not seem to clearly prohibit a
borrowing such as the apparently unpronouncible "spharage", so he may
have the same problem we do if he ever tries to computerize his
'unambiguous' algorithm and process that last example.

The other technique, used when a potentially syllabic consonant is the
second letter in the cluster, is to make the consonant syllabic, and
then >WRITE THEM WITH DOUBLED LETTERS<. (They do not do this in other cases
where they have syllabic consonants, hence this violates the concept of
having only one way to spell a given phoneme pattern).

(e.g. retrovirus ->retrroviri).

This forces a syllable break between r and o, and again the result could
never be confused, at least with any other type of predicate word.  This
violates TLI's stated rules against double letters in a consonant
cluster, but otherwise is not proscribed - hence "trroviri" should also
be possible, and the front of the word falls off here too.

But these two ways of 'repairing' borrowing problems might be valid, and
would avoid the problem, if TLI chose to write their rules a bit more
tightly, as LLG has now (more-or-less) done.

Other methods of borrowing are permitted by TLI in theory, just as
Lojban permits other methods of borrowing other than the 'fast route'
that we have promised by the "glue a rafsi on the front" technique.  But
JCB, as well as LLG, have reached the same conclusion - that defining
the bounds of what is valid so as to test such inventions/borrowings
on-the-fly accurately for validity, isn't a likely possibility.

***