Learning Boolean read-once formulas with arbitrary symmetric and constant fan-in gates

  • Authors:
  • Nader H. Bshouty;Thomas R. Hancock;Lisa Hellerstein

  • Affiliations:
  • Department of Computer Science, The University of Calgary, 2500 University Drive N.W., Calgary, Alberta, Canada T2N 1N4;Aiken Computation Laboratory, Harvard University, 33 Oxford Street, Cambridge, MA;Department of EECS, Northwestern University, 2145 Sheridan Road, Evanston, IL

  • Venue:
  • COLT '92 Proceedings of the fifth annual workshop on Computational learning theory
  • Year:
  • 1992

Quantified Score

Hi-index 0.00

Visualization

Abstract

A formula is read-once if each variable appears on at most a single input. Angluin, Hellerstein, and Karpinski have shown that boolean formulas with AND, OR, and NOT gates are exactly identifiable in polynomial time using membership and equivalence queries [AHK89]. Hancock and Hellerstein have generalized this to allow a wider subclass of symmetric basis functions [HH91]. We show a polynomial time algorithm in this model for identifying read-once formulas whose gates compute arbitrary functions of fan-in k or less for some constant k (i.e. any f :{0,1}1≤c≤k → {0,1}). We further show that if there is a polynomial time membership and equivalence query algorithm to identify read-once formulas over some set of functions B that meets certain technical conditions, then there is also such an algorithm to identify read-once formulas over B&ugr;{f:{0,1}1≤c≤k → {0,1}}. Finally, we extend the previous results to show that there is a polynomial time identification algorithm for read-once formulas over the basis of all symmetric functions (and hence also over the union of arbitrary symmetric and arbitrary constant fan-in gates). Given standard cryptographic assumptions, none of these results are possible for read-twice formulas.