ISSN:
1573-7470
Keywords:
Frege proofs
;
propositional calculus
;
parallel complexity
;
NC, free variable equational logic
;
resolution proof
Source:
Springer Online Journal Archives 1860-2000
Topics:
Computer Science
,
Mathematics
Notes:
Abstract Usingsequential, machine-independent characterization of theparallel complexity classesAC k andNC k , we establish the following conjecture of S.A. Cook. There is a free variable equational logicALV with the property thatif f, g are function symbols forALOGTIME computable functions for which “f=g” is provable inALV, then there are polynomial size Frege proofs for the infinite family {|f=g| m n :n, m∈ℕ} of propositional tautologies. Here, the propositional formula |f=g| m n expresses the equality off andg on inputs of length at mostn, provided that the function values are of length at mostm. We establish a related result with constant formula-depth polynomial size Frege proofs for a systemAV related to uniformAC 0 functions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01531023
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