We present logspace algorithms for the canonical labeling problem and the representation problem of Helly circular-arc (HCA) graphs. The first step is a reduction to canonical labeling and representation of interval intersection matrices. In a second step, the Delta trees employed in McConnell's linear time representation algorithm for interval matrices ... more >>>

A couple of years ago, Blais, Brody, and Matulef put forward a methodology for proving lower bounds on the query complexity
of property testing via communication complexity. They provided a restricted formulation of their methodology
(via ``simple combining operators'')
and also hinted towards a more general formulation, which we spell ... more >>>

Resolution trees with lemmas ($\mathrm{RTL}$) are a resolution-based propositional proof system that is related to the DPLL algorithm with clause learning. Its fragments $\mathrm{RTL}(k)$ are related to clause learning algorithms where the width of learned clauses is bounded by $k$.

For every $k$ up to $O(\log n)$, an exponential separation ... more >>>