[SCL] REQUEST FOR FEDBACK: core syntax

[pat hayes]

>Quick comments below.
>
>Jay
>
>----- Original Message -----
>From: "pat hayes" <phayes at ihmc.us>
>To: <scl at philebus.tamu.edu>
>Sent: Sunday, December 21, 2003 11:52
>Subject: [SCL] REQUEST FOR FEDBACK: core syntax
>
>
>>  Guys, I'd appreciate feedback (on something more important than
>>  terminology :-).
>>
>>  After thrashing around for a while, I think that the best choice for
>>  the 'core' syntax is a KIF-style syntax, but tweaked a little to make
>>  it easier to read.  Chief changes are these:
>>
>>  1.  No explicit syntactic marking of variables: a variable is just a
>>  name which is bound by a quantifier. This makes the examples a lot
>>  less ugly to read for many people and gets rid of the need to handle
>>  free vars as a special case in the MT.
>
>I find this convention awkward, not more readable. It means having to check
>back to the quantifier prefix to distinguish individual constants from
>variables.

Not if one consistently uses x y z etc. for variables. The informal 
convention is easier to read but not workable as a general-purpose 
syntactic convention.

>More processing and eye movement than less, I think.
>
>>
>>  2.  No explicit marking for forall and &: a conjunction is just a
>>  list of sentences and the unmarked quantifier case is the forall.  So
>>  for example this KIF
>>
>>  (forall (?x ?y)(implies (and (P ?x)(P ?y)) (P ?x ?y) ))
>>
>>  would look like this:
>>
>>  (x y)(implies ((P x)(P y)) (P x y) ))
>
>
>I don't find this convention of dropping 'and' readable either.

Yes, OK, now abandoned. Nobody liked it but me, it seems.

>I doubt that
>many others would too. Your convention requires an extra parsing effort on
>the part of a reader to supply the missing element -- one has to check
>parentheses carefully (my eyesight isn't great), whereas a big 'and'
>supplies a useful point of reference.
>
>No doubt, both this and the proceeding effort would become habitual and
>quicker over time, but I suspect there's still extra processing involved,
>and these aren't not customary to a large audience.

Indeed. Thanks for the feedback.

Pat

-- 
---------------------------------------------------------------------
IHMC	(850)434 8903 or (650)494 3973   home
40 South Alcaniz St.	(850)202 4416   office
Pensacola			(850)202 4440   fax
FL 32501			(850)291 0667    cell
phayes at ihmc.us       http://www.ihmc.us/users/phayes