P != NP, propositional proof complexity, and resolution lower bounds for the weak pigeonhole principle

Ran Raz P != NP, propositional proof complexity, and resolution lower bounds for the weak pigeonhole principle http://arxiv.org/abs/cs.CC/0304041 2003 CoRR cs.CC/0304041 db/journals/corr/corr0304.html#cs-CC-0304041