Lower Bounds for a Proof System with an Expentential Speed-up over Constant-Depth Frege Systems and over Polynomial Calculus.

Jan Krajícek Lower Bounds for a Proof System with an Expentential Speed-up over Constant-Depth Frege Systems and over Polynomial Calculus. 85-90 1997 conf/mfcs/1997 MFCS db/conf/mfcs/mfcs97.html#Krajicek97 http://dx.doi.org/10.1007/BFb0029951