The symmetry rule in propositional logic

Automated Reasoning with Analytic Tableaux and Related Methods, Lecture Notes in Artificial Intelligence 1847, ed. Roy Dyckhoff, 2000

2010

In this paper the proof complexities of some classes of quasi-hard determinable ( n Tsgf ) and hard determinable ( n ψ ) formulas are investigated in some refutation propositional systems. It is proved that 1) the number of proof steps of n Tsgf in ) (lin R (Resolution over linear equations) and + ' GCNF permutation (cut- free Gentzen type with permutation) systems are bounded by p( n Tsgf 2 log ) for some polynomial p(), 2) the formulas n ψ require exponential size proofs in + ' GCNF permutation. It is also shown that Frege systems polynomially simulate + ' GCNF permutation and any Frege system has exponential speed-up over the + ' GCNF permutation.

Lecture Notes in Computer Science, 2002

Theoretical Computer Science, 2007

University of Oxford, PRG technical monographs, 1990

1985

Annals of Pure and Applied Logic, 2014

Lecture Notes in Computer Science, 2011

Breve Historia de la Argentina, 1997

Pensada como una obra destinada a «suscitar la reflexión sobre el presente y el futuro del país» esta Breve historia de la Argentina se ha convertido, con los años, en un libro clásico. Obra de síntesis, pero a la vez de ideas, en sus páginas no sólo se encuentran hechos sino también interpretaciones que generan polémicas y suscitan opiniones encontradas. Escrito en 1965, fue actualizado