Reducibility of pointlike problems

Reducibility of Pointlike Problems

We show that the pointlike and the idempotent pointlike problems are reducible with respect to natural signatures in the following cases: the pseudovariety of all finite semigroups in which the order of every subgroup is a product of elements of a fixed set π of primes; the pseudovariety of all finite semigroups in which every regular J-class is the product of a rectangular band by a group from...

Reducibility Among Combinatorial Problems

Corrigendum: Space-Bounded Reducibility among Combinatorial Problems

1. 2. where I t has been pointed out that the S(')-bounded rudimentary predicates as given by Definition 6 of [1] do not possess the property asserted in the paragraph which starts on page 73 and ends on page 74. This may be corrected by replacing points 1, 2, and 3 of Definition 6 by the following: a(x, i, a) and ~ ( x , i, a) are in RUD s . I f c is a positive integer then both Q(x, u, v, w) ...

Borel-piecewise continuous reducibility for uniformization problems

We study a fine hierarchy of Borel-piecewise continuous functions, especially, between closed-piecewise continuity and Gδ-piecewise continuity. Our aim is to understand how a priority argument in computability theory is connected to the notion of Gδ-piecewise continuity, and then we utilize this connection to obtain separation results on subclasses of Gδ-piecewise continuous reductions for unif...

Sparse Variations and Reducibility among Prediction Problems Authors :

We investigate the relationship between two di erent notions of reducibility among prediction (learning) problems within the distribution-free learning model of Valiant (PAC learning model [7, 2].) The notions of reducibility we consider are the analogues for prediction problems of the many-one reducibility and of the Turing reducibility. The former is the notion of prediction preserving reduci...