Arnold Beckmann
Journal of Logic and Computation 2005, 15: 433-446
Publication year: 2005

We define the notion of the uniform reduct of a propositional proof system as the set of those bounded formulas in the language of Peano Arithmetic which have polynomial size proofs under the Paris-Wilkie-translation. With respect to the arithmetic complexity of uniform reducts, we show that uniform reducts are Π^0_1-hard and obviously in Σ^0_2. We also show under certain regularity conditions that each uniform reduct is closed under bounded generalisation; that in the case the language includes a symbol for exponentiation, a uniform reduct is closed under modus ponens if and only if it already contains all true bounded formulas; and that each uniform reduct contains all true Π^b_1(α)-formulas.

One Response to “Uniform proof complexity”

  1. Arnold

    Steve Cook made a comment on Problem 2.
    He showed that the existence of a proof system whose uniform reduct equals
    the set of all true bounded formulas is equivalent to the existence of
    an optimal proof system.
    Cook’s Comments (ps-file), in arXiv