The scalability of submodular optimization methods is critical for their usability in practice. In this paper, we study the reducibility of submodular functions, a property that enables us to reduce the solution space of submodular optimization problems without performance loss. We introduce the concept of reducibility using marginal gains. Then we show that by adding perturbation, we can endow...

A c.e. real x is Solovay reducible to another c.e. real y if x can be approximated at least as efficiently as y by means of increasing computable sequences of rational numbers. The Solovay reducibility classifies elegantly the relative randomness of c.e. reals. Especially, the c.e. random reals are complete unter the Solovay reducibility for c.e. reals. In this paper we investigate an extension...

We study the structure of Σ1 equivalence relations on hyperarithmetical subsets of ω under reducibilities given by hyperarithmetical or computable functions, called h-reducibility and FF-reducibility, respectively. We show that the structure is rich even when one fixes the number of properly Σ1 (i.e. Σ 1 1 but not ∆ 1 1) equivalence classes. We also show the existence of incomparable Σ1 equival...

Introduction Investigation of the infinite behavior of computing devices is of great interest for computer science because many hardware and software concurrent systems (like processors or operating systems) may not terminate. The study of infinite computations is important for several branches of theoretical computer science, including verification and synthesis of reactive computing systems [...

In this paper the reducibility and factoring for the homogeneous linear ODE operator of higher order is studied mainly for the 2nd order case. The determination of reducibility and the construction of factors are not difficult for the 2nd order ODE if the coefficients of the factorization are restricted to polynomials. The decision and the construction are also possible when the coefficients of...

In this work we investigate the hardness of a computational problem introduced in the recent work of Baumslag et al. in [3, 4]. In particular, we study the Bn-LHN problem, which is a generalized version of the learning with errors (LWE) problem, instantiated with a particular family of non-abelian groups (free Burnside groups of exponent 3). In our main result, we demonstrate a random self-redu...

We study reducibility for nowhere-zero flows. A reducibility proof typically consists of showing that some induced subgraphs cannot appear in a minimum counter-example to some conjecture. We derive algebraic proofs of reducibility. We define variables which in some sense count the number of nowhere-zero flows of certain type in a graph and then deduce equalities and inequalities that must hold ...

Computability theorists have studied many different reducibilities between sets of natural numbers including one reducibility (≤1), many-one reducibility (≤m), truth table reducibility (≤tt), weak truth table reducibility (≤wtt) and Turing reducibility (≤T ). The motivation for studying reducibilities stronger that Turing reducibility stems from internally motivated questions about varying the ...

Reducibility has been used to prove a number of properties in the λ-calculus and is well known to offer on one hand very general proofs which can be applied to a number of instantiations, and on the other hand, to be quite mysterious and inflexible. In this paper, we look at two related but different results in λ-calculi with intersection types. We show that one such result (which aims at givin...