PEP 308: Rejection of C ?? T || F

[Terry Reedy]

"Steven Taschuk" <staschuk at telusplanet.net> wrote in message
news:mailman.1045168419.4862.python-list at python.org...
> constructing sets of sequences.  (Incidentally, | as a logical
> operator in mathematics is afaik never alternation, but always
> alternative denial: p | q <=> not (p and q) <=> not p or not q.  I
> think this notation dates from at least the 1910s, and it might
> even occur in Russell and Whitehead's _Principia_.)

Half wrong, right, don't know.  Sheffer used | in 1913 for his
postulates for Boolean algebra.  By Boolean duality (where you swap T
with F and and with or), p|q can be consistently interpreted as either
not(p or q) or not(p and q), but I this the former is how it is
thought of more often.

Terry J. Reedy