Dear all:
My old logic book (Logic for Computer Science, 1985)
has been out of print for at least twelve years.
I just resurected the TEX files and even improved
the drawings. This updated version, with all known typos
and mistakes fixed, is available on-line (free!) at
http://www.cis.upenn.edu/~jean/gbooks/logic.html
Have fun!
- Jean Gallier