Jim Henry writes:
> 2009/5/4 René Uittenbogaard <[log in to unmask]>:
>> We know that "but" is logically nothing more than "and" (both
>> constituents are true).
>> But is it symmetrical or asymmetrical?
> It seems to me that "but" and "although"
> are mirative forms of "and" -- that is, one asserts
> that both propositions are true, and also expresses
> surprise at the fact.  ...

That's exactly how I handle it in Qþyn|gài, too: 'but' is simply like
'and', plus additional adverbials (or other bells and wistles) to
convey the surprise about the fact that both are true.  In Qþyn|gài,
there's the category if evidence/mood to do this quite elegantly, e.g.

   [FACT] it's rained AND [OWN EYES] coat is dry.

There's also the degree category to be used with all kinds of scales,
and it has as value 'UNEXPECTED', you can use:

   [FACT] it's rained AND [OWN EYES] coat is dry_DEGREE:UNEXPECTED.

So the asymmetry in 'but' and 'although' is in the adverbial/evidence,
not in the logic.