Le 13-janv.-06, à 19:13, Benjamin Udell wrote in part:
I'm wondering whether we mean the same thing by "truth preservation."
I mean the validity of such arguments as exemplified (in trivial
forms) by "p, ergo p" and "pq, ergo p" or whatever argument such that
the conclusion is "contained" in the premisses. Or maybe I've been
using the word "deductive" in too broad a sense?
Actually it is the contrary. What you describe is classical truth
preservation, which occurs with the classical deductive rules (so that
they are sound and complete). In general "truth preservation" is a
semantics dependant concept, where semantics can sometimes be given by
some mathematical structures. I don't want to be too technical at this
(Mathematically a semantics is a subspaces' classifier)
How did you guess that I currently have patience and time on my hands?
Thanks for witnessing the interest. I wish only I would have more time
for now. I have the patience I think :-)