I learned how to use nested scopes. It's too bad that Python didn't have
them before! As explained at
http://www.norvig.com/python-lisp.html,
Python Pre-2.1 did not have lexical scopes. In Python before
version 2.1 there were only two variable scopes per module: global
scope and function scope. In Python 2.1, released in April 2001, if
you do "from __future__ import nested_scopes", you add a third
scope, block nested scope. In Python 2.2, this is the default
behavior. Without nested scopes you are allowed to nest a function
definition (or a lambda) within another, but the inner function can
only reference global variables, not the variables of the outer
function.
I taught another Python class at EFF. It's a lot of fun to teach people
to program in Python.
Using my logic gates code, and assuming you start with BITS=3, you can
do things like
> >>> xor_gate = gate(150)
> >>> print xor_gate[(0, 1, 1)]
> 0
> >>> xor = lambda x: xor_gate[x]
> >>> print map(xor, map(binary_tuple, range(8)))
> [0, 1, 1, 0, 1, 0, 0, 1]
A huge amount is known about Boolean functions,
and I don't know most of it.
I found Cox's conjecture very interesting:
the hardest-to-realize Boolean function of n variables using AND and
OR (and starting with the values and their complements) is the n-input
XOR. This seems very plausible, but I don't know how to prove it.
I'm sure PLD people are still studying efficient ways of realizing
Boolean truth tables.
The AT&T telemarketers are really persistent, and don't seem to keep
any record of whom they spoke to, or when, or what they heard. So I've
personally gotten over a dozen calls from them. And I've now explained
for the third time that we don't have a default long-distance carrier
at all, and we select one each time we want to make a long-distance
call. So therefore we aren't willing to adopt AT&T or anyone else as
our default carrier.
However often I explain that, and also talk about
VarTec's
lower-than-AT&T long distance rates, AT&T keeps calling me back
as though they've never spoken with me before.
"The most important thing we want to do is be true to our own values
in football, which we believe are the values reflected and brought to
bear more broadly in our society," he said.
(NFL Commissioner
Paul Tagliabue)
It's been a long time since I experienced the wonders of seismology
puns, but this appeared in Sumana's diary:
Matt told us that one could drive to Half Moon Bay to cross from one
tectonic plate to another. I asked whether he enjoys doing that.
"Yes," he said. "To a fault."
