🚀 go-pugleaf

Richard A. O'Keefe's (ok@goanna.cs.rmit.oz.au) seems to have
misunderstood my original posting, and interpreted it as
a "How can I do this in Prolog?" question or even a 
"See how stupid X is in Prolog!" comment.

As I said at the start of my original message, this is a
question of *conceptualization*, I am *not* suggesting that
the DCG axioms are wrong, but that they are based on a conceptualization
of grammar that differs from one in which ambiguity is represented
by a disjunction of alternative readings or trees.  Much recent
work on feature structures represents, say, lexical ambiguity as
a *disjunction* of possible feature values, for example, so
I don't think this conception is incoherent.

I agree that there is a coherent interpretation of DCGs where
predicates like my "means" are interpreted as "is-a-possible-meaning-of",
but so what?  This is *not* the conception I want to axiomatize.

>> First, you can deny that natural language ambiguity really leads to
>> disjunctive, rather than conjunctive, consequents.

But of course that is exactly what you are doing - you are saying
that under the appropriate conception the consequents *are* conjunctive.

Let's see where that gets you...

>If you want something that gives you *all* the presuppositions that are
>implicit in a particular reading, you will have to write a predicate
>that *DOES* that, i.e. that returns a structure representing a _set_ of
>presuppositions, e.g.
>	presupposes(S, [X^man(X),Y^woman(Y)])

So if S is ambiguous, we get something like

	presupposes(S, [P1,P2,P3]), presupposes(S, [Q1,Q2]).

How can we read this in English?

	S presupposes P1 and P2 and P3, *or* it presuposses Q1 and Q2.

Isn't it a little funny that the set construction is used to
express English conjunction, and the conjunction connective is
used to express English disjunction?

I think I know what Richard will say - we must also interpret
"presupposes" as "is a possible set of presuppositions of".

That works, but what if that isn't the interpretation I am
interested in?  Let me be clear: I am not after a Prolog program
that "solves my problems", I am after an axiomatization that
expresses my conceptualization, or some principled explanation
of why such an axiomatization does not exist.

Note, by the way, what I am *not* saying.  I am *not* saying that
there is anything wrong with doing things the Prolog way: given the
limitations of Horn logic (no disjunctive conclusions) it's
clear that something like this has to be done if you want to
use Prolog.

But in full first-order logic it is a little strange to have to
interpret conjunction as disjunction, given that the language
has the means to express disjunction directly.

>> But I think there is
>> a deeper issue here -- why doesn't the straight-forward approach
>> sketched above work?

>Because it's WRONG.  It simply doesn't say what you think it says.
> ... What you are saying is not what you mean.

Huh?  I realized before I posted the article that the DCG axioms 
don't conceptualize of the "means" relation the way I do, that's
*why* I posted the article.  I am asking for *other axioms*
that do express my conceptualization, or else principled
reasons for why such an axiomatization does not exist.

If you think that my conceptualization is "WRONG", maybe you
might like to explain why?  The existence of another conceptualization
does *not* show this.

Addenda:  
  1.  In my previous article I forgot to put in an
axiom that requires "means-in-context" (or whatever it was called)
to be single-valued.

  2.  Jochen Doerre and Andreas Eisle here at the IMSV have pointed
out that my disjunctively formulated lexical entries don't correspond
to my intended interpretation, since the same word can appear multiple
times in one utterance.