Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!ll-xn!mit-eddie!rutgers!okstate!norman
From: norman@a.cs.okstate.edu (Norman Graham)
Newsgroups: comp.lang.misc
Subject: Re: Unification of Paradigms
Summary: The relationship between unification and function invocation.
Message-ID: <3938@okstate.UUCP>
Date: 21 Sep 88 15:49:40 GMT
References: <3923@okstate.UUCP> <8943@srcsip.UUCP>
Organization: Oklahoma State Univ., Stillwater
Lines: 44

From article <8943@srcsip.UUCP>, by shankar@srcsip.UUCP (Subash Shankar):
> First, unification
> is much more general then function invocation, for obvious reasons.

I did not have in mind the replacement of unification with function
invocation.  I was thinking of unification as a function from
assertions and goals to answers.  

Of course, what I intended in the original posting was to incorporate
basic ideas from other paradigms into the paradigm that I'm most 
comfortable with (ie. procedural).  I've only now become aware of that 
intention, and can now see the blind spot that it caused.  (Incidentally,
I am saddened by the crippling of procedural languages by static
type systems; lack of first class citizenship for all objects; 
inability to specify things such as lazy or eager evaluation,
the environment to operate in, and to use a store or not; and the 
lack of higher order type systems.  The current procedural languages
can be extended a great deal before they cease to be procedural.)
 
> Now, if you were to say that functions only provide syntactic sugar for a
> handful of predicates written in logic languages, I would probably agree :-)

You may smile, but you raise a case that I had not considered.  Now it
looks like we have four choices:

1) function invocation and unification exit as independent concepts,
   side-by-side in the language.

2) functions are implemented as some sort of restricted unification.

3) unification is implemented as a function.

4) function invocation and unification do not exist in the same language.


In the future, I'll take O'Keefe's advise and not pontificate about
topics I know I know nothing about.  But since we're already going
on this topic, let's beat it around a bit.

-- 
Norman Graham                            Oklahoma State University
  Internet:  norman@a.cs.okstate.edu     Computing and Information Sciences
      UUCP:  {cbosgd, ihnp4,             219 Mathematical Sciences Building
              rutgers}!okstate!norman    Stillwater, OK  74078-0599