[SCL] Suggestion for SCL extension module

[John F. Sowa]

Pat,

This is an interesting subject that we can discuss in January,
until then we have a more narrowly defined task to do.

>Summary: the set of modalities being considered is much more 
>open-ended, eg cases where every program in a PL corresponds to a 
>distinct modality. So we need a more open-ended syntax than we might 
>have needed for Prior, Dunn and Kripke.

I'm not convinced.  The reason why I have advocated a move
from Kripke's worlds to Dunn's laws and facts is that the
laws give us something more definite to work with.  And to
the extent that we can specify a computer program by a set
of constraints, we can use those constraints as the laws
that define a Dunn-style modality.

But that is a topic for January.

John