  This is yet another version of the course notes in chao-dyn/9407003. Here we
change the universal Turing machine that is used to measure program-size
complexity so that the constants in our information-theoretic incompleteness
theorems are further reduced. This is done by inventing a more complicated
version of lisp in which the parentheses associating defined functions with
their arguments can be omitted. This is the third and last version of my course
notes. It is not clear to me which is to be preferred, so all three have been
made available for comment.
