[SCL] Re: (SCL) Getting a move on

[John F. Sowa]

Chris, Pat, et al.,

There are several important requirements for CL/SCL:

  1. Support existing users of languages such as KIF, CGs,
     etc., with a semantic foundation that is upward
     compatible (with some hopefully minor exceptions)
     with what they have been using.

  2. Present that foundation and its concrete embodiment
     in usable logic notations in time to be used for
     projects that have a pressing need for them ASAP
     (where ASAP is approximately June 2003).

  3. Do not create unnecessary impediments or constraints
     that would undermine ongoing research into more general
     foundations that could support powerful extensions
     for the future.

I believe that we can meet these requirements by producing
a first version of a standard that can be presented to ISO,
W3C, and others along the lines that Pat has proposed as SCL.

I also believe that SCL could be defined in the more powerful
CL foundation that Pat and Chris have been developing.  Therefore,
SCL could be presented as v 1.0 next summer with a more general
CL to follow as v 2.0 at some time after that.

Re seqvars:  For full CL, we have been trying to avoid any
ontological commitments whatever.  But for SCL, it would be
possible to compromise the purity by including an ontology for
integers and lists (which are needed in almost all applications).
Then the lists could be used to support sequences as currently
used in those KIF applications that need seqvars.  This approach
isn't as elegant or powerful as the full CL proposal, but it
would be a valuable stop-gap that would enable us to finish
the definition of SCL by June.  Meanwhile, work on the CL
standard for v 2.0 would demonstrate how SCL could be supported
in a upward-compatible fashion.

John Sowa