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QueryLimited Reducibilities
, 1995
"... We study classes of sets and functions computable by algorithms that make a limited number of queries to an oracle. We distinguish between queries made in parallel (each question being independent of the answers to the others, as in a truthtable reduction) and queries made in serial (each question ..."
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Cited by 41 (14 self)
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We study classes of sets and functions computable by algorithms that make a limited number of queries to an oracle. We distinguish between queries made in parallel (each question being independent of the answers to the others, as in a truthtable reduction) and queries made in serial (each question being permitted to depend on the answers to the previous questions, as in a Turing reduction). We define computability by a set of functions, and we show that it captures the informationtheoretic aspects of computability by a fixed number of queries to an oracle. Using that concept, we prove a very powerful result, the Nonspeedup Theorem, which states that 2 n parallel queries to any fixed nonrecursive oracle cannot be answered by an algorithm that makes only n queries to any oracle whatsoever. This is the tightest general result possible. A corollary is the intuitively obvious, but nontrivial result that additional parallel queries to an oracle allow us to compute additional functions; t...
Bounded Query Classes and the Difference Hierarchy
 Archive for Mathematical Logic
, 1995
"... Let A be any nonrecursive set. We define a hierarchy of sets (and a corresponding hierarchy of degrees) that are reducible to A based on bounding the number of queries to A that an oracle machine can make. When A is the halting problem K our hierarchy of sets interleaves with the difference hierarch ..."
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Cited by 15 (12 self)
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Let A be any nonrecursive set. We define a hierarchy of sets (and a corresponding hierarchy of degrees) that are reducible to A based on bounding the number of queries to A that an oracle machine can make. When A is the halting problem K our hierarchy of sets interleaves with the difference hierarchy Current address: Department of Computer Science, Yale University, 51 Prospect Street, P.O. Box 2158 Yale Station, New Haven, CT 06520. Supported in part by NSF grant CCR8808949. Part of this work was completed while this author was a student at Stanford University supported by fellowships from the National Science Foundation and from the Fannie and John Hertz Foundation. y Supported in part by NSF grant CCR8803641. z Part of this work was completed while this author was on sabbatical leave at the University of California, Berkeley. on the r.e. sets in a logarithmic way; this follows from a tradeoff between the number of parallel queries and the number of serial queries needed to...
On TruthTable Reducibility to SAT and the Difference Hierarchy over NP
, 1987
"... We show that polynomial time truthtable reducibility via Boolean circuits to SAT is the same as log space truthtable reducibility via Boolean formulas to SAT and the same as log space Turing reducibility to SAT . In addition, we prove that a constant number of rounds of parallel queries to SAT ..."
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Cited by 13 (2 self)
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We show that polynomial time truthtable reducibility via Boolean circuits to SAT is the same as log space truthtable reducibility via Boolean formulas to SAT and the same as log space Turing reducibility to SAT . In addition, we prove that a constant number of rounds of parallel queries to SAT is equivalent to one round of parallel queries.
Extending Temporal Logic Programming with Choice Predicates Nondeterminism
 Journal of Logic and Computation
, 1994
"... In temporal logic programming, a stream can be specified by a singlevalued, timevarying predicate which, at any given moment in time, represents the corresponding element in the stream. However, due to inherent nondeterminism in logic programming, timevarying predicates do not necessarily repres ..."
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Cited by 6 (3 self)
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In temporal logic programming, a stream can be specified by a singlevalued, timevarying predicate which, at any given moment in time, represents the corresponding element in the stream. However, due to inherent nondeterminism in logic programming, timevarying predicates do not necessarily represent singlevalued relations at any given moment in time. Choice predicates are also timevarying predicates, but, in principle, they act like a dataflow node with multiple input lines which nondeterministically selects one of its inputs as output. Therefore they are guaranteed to be singlevalued at all moments in time, and they can be regarded as representing "nondeterministic" streams. Users do not define choice predicates, they are supplied automatically for all predicates defined in temporal logic programs. Inputs to choice predicates are supplied by the corresponding predicates. When the connection between choice predicates and the corresponding predicates is established, we obtain no...
Parsimony Hierarchies for Inductive Inference
 Journal of Symbolic Logic
"... Freivalds defined an acceptable programming system independent criterion for learning programs for functions in which the final programs were required to be both correct and "nearly" minimal size, i.e, within a computable function of being purely minimal size. Kinber showed that this parsimony requi ..."
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Cited by 2 (1 self)
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Freivalds defined an acceptable programming system independent criterion for learning programs for functions in which the final programs were required to be both correct and "nearly" minimal size, i.e, within a computable function of being purely minimal size. Kinber showed that this parsimony requirement on final programs limits learning power. However, in scientific inference, parsimony is considered highly desirable. A limcomputable function is (by definition) one calculable by a total procedure allowed to change its mind finitely many times about its output. Investigated is the possibility of assuaging somewhat the limitation on learning power resulting from requiring parsimonious final programs by use of criteria which require the final, correct programs to be "notsonearly" minimal size, e.g., to be within a limcomputable function of actual minimal size. It is shown that some parsimony in the final program is thereby retained, yet learning power strictly increases. Considered, then, are limcomputable functions as above but for which notations for constructive ordinals are used to bound the number of mind changes allowed regarding the output. This is a variant of an idea introduced by Freivalds and Smith. For this ordinal notation complexity bounded version of limcomputability, the power of the resultant learning criteria form finely graded, infinitely ramifying, infinite hierarchies intermediate between the computable and the limcomputable cases. Some of these hierarchies, for the natural notations determining them, are shown to be optimally tight.