> This is a logical principle (that a statement of the form P => Q is equivalent toits
> contrapositive Q => P) that we (most of us) assume because we get a theory
> that seems to make sense to us.
I meant to say that P => Q is equivalent to not Q => not P, which
is its contrapositive.
Bill Haloupek
haloupekb@uwstout.edu
http://www.mscs.uwstout.edu/~billh/home.html