From: usubrama@magnus.acs.ohio-state.edu (Uma M Subramanian)
Subject: Re: Sanskrit and the Unity of India
Organization: The Ohio State University
Date: Tue, 15 Sep 1992 00:03:50 GMT

Warning: This is a long and technical article. Hit 'n' now if you have
no burning desire to be enlightened on this matter.

In article <1992Sep14.053247.27922@cis.ohio-state.edu> jayasim@platypus.cis.ohio-state.edu (D Jayasimha) writes:
>In article <1992Sep10.045952.27271@magnus.acs.ohio-state.edu> usubrama@magnus.acs.ohio-state.edu (Uma M Subramanian) writes:
>>
>>From a linguist's point of view, it makes no sense to claim that some
>>natural language NL is "best-suited" for use as a computer language, since
>>all natural langauges known to us lie within the same level of complexity.
>...
>[some stuff deleted]
>...
>>Secondly, this kind of "cleaning up", ridding of all ambiguities,
>>can be done for ANY human language. Of course, the result wouldn't
>...
>[some stuff deleted]
>>
>>Uma Subramanian
> 
>
>Thanks- that was an informative article but I have some differences with 
>your opinion.

Of course,that's fine.

>Caveat: I lay no claims to any formal training in linguistics.  My comments
>are those of an interested layperson- feel free to correct me.  I will 
>confine my comments to English and Sanskrit- two languages with which I 
>have some degree of familiarity.

Caveat: My Sanskrit is shaky at best (the result of paying more attention
to my Sanskrit teacher's snuff-inhaling habits than to his lessons); so
I can only give some pointers to the kinds of structures that might
be ambiguous in Sanskrit rather than give actual examples (though I'll
try my best to be specific). Please feel free to add to/correcct the
'facts' I give below. I speak as a linguist, and not as someone who
knows Sanskrit.

>We are not comparing languages w.r.t. their overall complexity or
>suitablility- rather, w.r.t. a particular property- that of suitability 
>as a computer language.

I apologize for not making the connection between the complexity issue
and suitability as a computer lg. clearer. All natural lgs. lie within
the same level of complexity (mathematically speaking) and in particular,
they are *at least* context-free, if not higher in the hierarchy. Hence,
they all have ambiguity, (i.e. two different derivations for some strings),
and therefore, not suitable as computer lgs. I might have failed to make
some part of this reasoning explicit.  

>I am rather surprised that you claim that all
>natural languages are "equivalent" even in this sense.  Let's say, for
>example, that a language be phonetic is the requirement in some
>application.  Surely, Sanskrit would win hands down compared to English.
>On the other hand, given a finite alphabet, some sounds cannot be
>"written down" in a phonetic language- this is, of course, a disadvantage
>but unimportant here.

I'm afraid I don't know exactly what you mean here. I'd be glad to
discuss this if I know what you have in mind. 

>Furthermore, Sanskrit, as we know of it today is not a true natural language
>in the same way as English or Swahili or Tamil is.  It is hardly spoken now-
>so colloquialisms, word overloading, need for economy of expression, etc. 
>have not been incorporated for the hundreds of years that it has not been 
>spoken.  Also, unlike most natural languages (perhaps with the exception 
>of Latin), Sanskrit has remained "Shastric" or formal- mainly because 
>a) the grammar has been close to "prescriptive" rather than being 
>"descriptive" (Paanini formalized the language in its early stage of 
>development), b) whenever Sanskrit took on the status of a language used 
>by commoners, it evolved into a different language (e.g. Paali, Maagadhi, 
>etc.), the original thus retaining its "purity" and formalism.

I agree with you completely here. And as I said in my previous response
on this, it is therefore an artificially cleaned-up linguistic system;
if the writers followed PaaNini's regulations, then we have no written
records of some syntactic patterns that would be ambiguous, which
doesn't necessarily mean that they didn't exist in the lg.

>Let's assume for a moment that the only disambiguities in Sanskrit arise
>because of the rules of Sandhi and Samaasa (cf. my previous posting
>on this topic)- I would not be surprised if this were indeed so.  

I can think of some other structures that could be ambiguous, even though
I wasn't able to glean any real-life examples from the few books I have.
Where you need to control for something to get the ambiguity, I'll
specify what needs to be controlled for; finally, note that the
existence of an unambiguous paraphrase doesn't make the ambiguity
go away, just as the existence of "With a telescope I watched the
man" doesn't make "I watched the man with a telescope" unambiguous.

(i) some sequence of ADJECTIVE + NOUN1 + CA + NOUN2 (CA)
(here 'ca' is the conjunction 'and'). THis is similar to the
Eglish 'old men and women' type of ambiguity. One needs to make
sure that NOUN1 and NOUN2 are the same number and gender so that
teh adjective is declined in a way taht makes it compatible with 
either just NOUN1 or both NOUN1 and NOUN2. (something like
'muditaah munayah ca raakshasah' before applying sandhi rules,
which could either mean 'delighted sages and delighted demons'
or 'delighted sages and (delighted-or-not) demons'). 

(ii) some sequence of ADVERB+SENTENCE1+SENTENCE2
(similar to the english 'the newspapers reported that he had
a heart attack yesterday' wehre the 'yesterday' could go with
the reporting part or the heart-attack part).

In Sanskrit, the adverb would be first, the heart-attack part
second, followed by 'iti' and then the reporting part.

(iii) (I'm less sure about this than I'm about the above two). 
Actually it's too much pain explaining this case -- if anyone's
interested, I can explain it on e-mail.

(iv) Try one of the various possibilities for "Sita waited for
Rama to return with a hoard of people". (try 'hoard of people'
in the instrumental followed by 'saha'.) One of the allowable
variations should give two readings, if my guess is right.

>Disallowing certain rules is certainly simpler than adding extra rules to
>disambiguate sentences in another language such as English where sentences
>can have multiple meanings- e.g., I saw a man on the hill with a telescope-

A priori, I don't know if one can say that disallowing certain rules is
simpler than adding extra rules, even though the suggestion I'm going
to make is of the 'disallowing rules' kind. See below.

>(also, I would expect that it would be non-trivial to prove that a set 
>of disambiguation rules are complete and consistent- am I correct?).

May be not. As you well know, structural ambiguities, (i.e. ambiguities of 
the type you mention in Englihs, and of the type I outlined in (i-iv), wehre
the multiple meanings are not a resultof one *word* having multiple
meanings), are intrinsic to context-free grammars and therefore
context-free langugaes. They arise because there exist more than
one rule that can generate the same string. Take teh string 'abcde'
and assume teh following CF rules:

S--> AB
A --> ab(c)
B --> (c)de

Now the string 'abcde' can be given two different parsings. Given 
some sequence of words in a natural language, when all other
conditions are met, there is always room for the possiblity that 
it has two different meanings. 

Now, to substantiate my claim taht this "cleaning up",
this disambiguation can be done for all languages, let me outline
an algorithm to do it: Take all sets of rules that would
result in the same string and eliminate all but one such
set. (For example, by this strategy, "I watched the man with
a telescope" will have only one derivation, and "With a telescope
I watched the man" is the only way of expressing the meaning that
was ruled out bythe elimination of the other derivation.) Since
the set of rules for any lg. is finite, and since it can be determined
which of these rules generate teh same sequences, this procedure
*is* sure to be complete and consistent. (Of course, those of
us in teh business of analyzing the messy thing that natural lgs.
are, know that coming up with all the rules for a lg. is no breeze.
But in theory, it can be complete and consistent.)

>jayasimha

Uma Subramanian

PS: THe main thrust of my previous response was this: a claim such
as "Sanskrit is best-suited for use as computer lg.", to a linguist,
has the flavor of "A three-year-old fathers a child" type of saucy
stories on the newsstand. For this to be true, Sanskrit ought
to be something very different from what we know human lgs. to be.
It has to be a much simpler lg., not on the same level with other
human lgs. in the hierarchy. Of course, it could be done artificially.

PPS: Most of what I say here is my own thinking -- comments welcome.