In a semantic resolution proof we operate with clauses only
but allow {\em arbitrary} rules of inference:

C_1 C_2 ... C_m
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C

Consistency is the only requirement. We prove a very simple
exponential lower bound for the size of bounded fanin semantic
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Having good algorithms to verify tautologies as efficiently as possible
is of prime interest in different fields of computer science.
In this paper we present an algorithm for finding Resolution refutations
based on finding tree-like Res(k) refutations. The algorithm is based on
the one of Beame and Pitassi \cite{BP96} ... more >>>

We prove a quasi-polynomial lower bound on the size of bounded-depth
Frege proofs of the pigeonhole principle $PHP^{m}_n$ where
$m= (1+1/{\polylog n})n$.
This lower bound qualitatively matches the known quasi-polynomial-size
bounded-depth Frege proofs for these principles.
Our technique, which uses a switching lemma argument like other lower bounds
for ... more >>>