Also:<p>Intro to Mathematical Philosophy: <a href="http://people.umass.edu/klement/russell-imp.html" rel="nofollow">http://people.umass.edu/klement/russell-imp.html</a><p>and Tractacus: Logico-Philosophicus: <a href="http://people.umass.edu/klement/tlp/" rel="nofollow">http://people.umass.edu/klement/tlp/</a>