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24
Logic and the Challenge of Computer Science
, 1988
"... Nowadays computer science is surpassing mathematics as the primary field of logic applications, but logic is not tuned properly to the new role. In particular, classical logic is preoccupied mostly with infinite static structures whereas many objects of interest in computer science are dynamic objec ..."
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Cited by 165 (16 self)
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Nowadays computer science is surpassing mathematics as the primary field of logic applications, but logic is not tuned properly to the new role. In particular, classical logic is preoccupied mostly with infinite static structures whereas many objects of interest in computer science are dynamic objects with bounded resources. This chapter consists of two independent parts. The first part is devoted to finite model theory; it is mostly a survey of logics tailored for computational complexity. The second part is devoted to dynamic structures with bounded resources. In particular, we use dynamic structures with bounded resources to model Pascal.
Toward Logic Tailored for Computational Complexity
 COMPUTATION AND PROOF THEORY
, 1984
"... Whereas firstorder logic was developed to confront the infinite it is often used in computer science in such a way that infinite models are meaningless. We discuss the firstorder theory of finite structures and alternatives to firstorder logic, especially polynomial time logic. ..."
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Cited by 87 (7 self)
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Whereas firstorder logic was developed to confront the infinite it is often used in computer science in such a way that infinite models are meaningless. We discuss the firstorder theory of finite structures and alternatives to firstorder logic, especially polynomial time logic.
Algebras of feasible functions
 in "Proc. 24th Annual IEEE Sympos. Found. Comput. Sci
, 1983
"... What happens if we interpret the syntax of primitive recursive functions in finite domains rather than in the (Platonic) realm of all natural numbers? The answer is somewhat surprising: primitive recursiveness coincides with LOGSPACE computability. Analogously, recursiveness coincides with PTIME com ..."
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Cited by 55 (5 self)
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What happens if we interpret the syntax of primitive recursive functions in finite domains rather than in the (Platonic) realm of all natural numbers? The answer is somewhat surprising: primitive recursiveness coincides with LOGSPACE computability. Analogously, recursiveness coincides with PTIME computability on finite domains (cf. [Sa]). Inductive definitions for some other complexity classes are discussed too.
The Expressive Power of Higherorder Types or, Life without CONS
, 2001
"... Compare firstorder functional programs with higherorder programs allowing functions as function parameters. Can the the first program class solve fewer problems than the second? The answer is no: both classes are Turing complete, meaning that they can compute all partial recursive functions. In pa ..."
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Cited by 30 (1 self)
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Compare firstorder functional programs with higherorder programs allowing functions as function parameters. Can the the first program class solve fewer problems than the second? The answer is no: both classes are Turing complete, meaning that they can compute all partial recursive functions. In particular, higherorder values may be firstorder simulated by use of the list constructor ‘cons’ to build function closures. This paper uses complexity theory to prove some expressivity results about small programming languages that are less than Turing complete. Complexity classes of decision problems are used to characterize the expressive power of functional programming language features. An example: secondorder programs are more powerful than firstorder, since a function f of type &lsqb;Bool&rsqb;〉Bool is computable by a consfree firstorder functional program if and only if f is in PTIME, whereas f is computable by a consfree secondorder program if and only if f is in EXPTIME. Exact characterizations are given for those problems of type &lsqb;Bool&rsqb;〉Bool solvable by programs with several combinations of operations on data: presence or absence of constructors; the order of data values: 0, 1, or higher; and program control structures: general recursion, tail recursion, primitive recursion.
Descriptive Complexity Theory over the Real Numbers
 LECTURES IN APPLIED MATHEMATICS
, 1996
"... We present a logical approach to complexity over the real numbers with respect to the model of Blum, Shub and Smale. The logics under consideration are interpreted over a special class of twosorted structures, called Rstructures: They consist of a finite structure together with the ordered field ..."
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Cited by 28 (8 self)
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We present a logical approach to complexity over the real numbers with respect to the model of Blum, Shub and Smale. The logics under consideration are interpreted over a special class of twosorted structures, called Rstructures: They consist of a finite structure together with the ordered field of reals and a finite set of functions from the finite structure into R. They are a special case of the metafinite structures introduced recently by Grädel and Gurevich. We argue that Rstructures provide the right class of structures to develop a descriptive complexity theory over R. We substantiate this claim by a number of results that relate logical definability on Rstructures with complexity of computations of BSSmachines.
Bounded Hyperset Theory and Weblike Data Bases
 Computational Logic and Proof Theory, 5th Kurt Gödel Colloquium, KGC’97, Springer LNCS
, 1997
"... this paper rather abstract, \static" settheoretic view on the WorldWide Web (WWW) or, more generally, on Weblike Data Bases (WDB) and on the corresponding querying to WDB. Let us stress that it is not only about databases with an access via Web. The database itself should be organized in the ..."
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Cited by 18 (5 self)
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(Show Context)
this paper rather abstract, \static" settheoretic view on the WorldWide Web (WWW) or, more generally, on Weblike Data Bases (WDB) and on the corresponding querying to WDB. Let us stress that it is not only about databases with an access via Web. The database itself should be organized in the same way as Web. I.e. it must consist of hyperlinked pages distributed among the computers participating either in global network like Internet or in some local, isolated from the outside world specic network based essentially on the same principles, except globality, and called also Intranet [15].
Tailoring Recursion for Complexity
 J. SYMBOLIC LOGIC
, 1995
"... We design functional algebras that characterize various complexity classes of global functions. For this purpose, classical schemata from recursion theory are tailored for capturing complexity. In particular we present a functional analogue of firstorder logic and describe algebras of the function ..."
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Cited by 13 (1 self)
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We design functional algebras that characterize various complexity classes of global functions. For this purpose, classical schemata from recursion theory are tailored for capturing complexity. In particular we present a functional analogue of firstorder logic and describe algebras of the functions computable in nondeterministic logarithmic space, deterministic and nondeterministic polynomial time, and for the functions computable by AC¹circuits.
Linear ordering on graphs, antifounded sets and polynomial time computability
 THEORETICAL COMPUTER SCIENCE
, 1999
"... It is proved definability in FO+IFP of a global linear ordering on vertices of strongly extensional (SE) finitelybranching graphs. In the case of finite SE graphs this also holds for FO+LFP. This gives capturing results for PTIME computability on the latter class of graphs by FO+LFP and FO+IFP, and ..."
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Cited by 11 (2 self)
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It is proved definability in FO+IFP of a global linear ordering on vertices of strongly extensional (SE) finitelybranching graphs. In the case of finite SE graphs this also holds for FO+LFP. This gives capturing results for PTIME computability on the latter class of graphs by FO+LFP and FO+IFP, and also on the corresponding antifounded universe HFA of hereditarilyfinite sets by a language \Delta of a bounded set theory BSTA. Oracle PTIME computability over HFA is also captured by an appropriate extension of the language \Delta by predicate variables and a bounded 2recursion schema. It is also characterized the type of corresponding linear ordering on the universe HFA and on its natural extension HFA 1 consisting of hereditarilyfinite antifounded sets with possibly infinite (unlike HFA) transitive closures.