Learning CNF Formulas from Uniform Random Solutions: Near-Tight Sample Complexity for Valiant's Algorithm

arXiv:2609.15268 · cs.LG, cs.DS · Submitted 2026-09-14 · Read on arXiv

cs.LG, cs.DS

Submitted: 2026-09-14

Updated: 2026-09-14

License: http://creativecommons.org/licenses/by/4.0/

The gist: We revisit Valiant's algorithm (Commun.

Terminology

Abstract

We revisit Valiant's algorithm (Commun. ACM'84) for learning n-variable CNF formulas with clause size k and variable degree d from i.i.d. uniform random solutions in the local lemma regime. For fixed t at least1, under k (1+1/t) d, Valiant's algorithm achieves total variation error epsilon with (n t/epsilon) sample complexity. For t>1, we prove a matching lower bound for Valiant's algorithm. At t=1 (covering 0<t<1), we show Valiant's algorithm has optimal sample complexity up to logarithmic factors by an information-theoretic lower bound Ω(n/epsilon).

Sources

Related papers