Hard Sets Are Hard to Find

Hard Sets are Hard to Find

We investigate the frequency of complete sets for various complexity classes within EXP under several polynomial-time reductions in the sense of resource bounded measure. We show that these sets are scarce: The sets that are complete under 6 p n ?tt-reductions for NP, the levels of the polynomial-time hierarchy, and PSPACE have p 2-measure zero for any constant < 1. The 6 p n c ?T-complete sets...

Combinatorial Morse Flows Are Hard to Find

We investigate the probability of detecting combinatorial Morse flows on a simplicial complex via a random search. It is really small, in a quantifiable way. CONTENTS

Short Proofs are Hard to Find

There Are No Sparse NPW-Hard Sets

In this paper we prove that, in the context of weak machines over IR, there are no sparse NP-hard sets.

[Aerococci: hard to find and classify].

Dear Editor, I read with interest the case report entitled " Aerococ-cus viridans urinary tract infection in a pediatric patient with secondary pseudohypoaldosteronism " by Leite and coworkers in Revista Argentina de Microbiología, volume 42, number 4. This report is important since it shows that aerococci can also cause disease in pediatric patients. Previous reports indicate that aerococci mo...