Conference article and Preprint:
Maria Luisa Bonet and Samuel R. Buss
"An Improved Separation of Regular Resolution from
Pool Resolution and Clause Learning (Extended Abstract)"
To appear in Theory and Applications of Satisfiability Testing (SAT), 2012..
Download conference version (extended abstract): PDF.
Download full version of paper (preprint): PDF.
Abstract: We prove that the graph tautology principles of Alekhnovich, Johannsen, Pitassi and Urquhart have polynomial size pool resolution refutations using only input lemmas as learned clauses and without degenerate resolution inferences. These graph tautology principles can be refuted by polynomial size DPLL proofs with clause learning, even when restricted to greedy, unit-propagating DPLL search.
Revised slides from related talk:
An Improved Separation of Regular Resolution from
Pool Resolution and Clause Learning
Workshop on Proof Complexity
BIRS, Banff, Canada
October 5, 2011
Download slides: PDF.