[SCL] REQUEST FOR FEDBACK: core syntax

[Jay Halcomb]

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. 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. 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.