Let's look at some messages from Principia Mathematica .... signaling events that occurred between year 1910 and now, year 2014.
, as it is often abbreviated, was an attempt to describe a set of axioms
and inference rules
in symbolic logic
from which all mathematical truths could in principle be proven.
The messages are via BLOG posts that are sub-page TITLES listed on the left of your computer screen. Select on a title.