temporalprogramming languages provide a powerful means for the description and implementation of dynamic systems. However, most temporal languages are based on linear time, a fact that renders them unsuitable for cer...
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temporalprogramming languages provide a powerful means for the description and implementation of dynamic systems. However, most temporal languages are based on linear time, a fact that renders them unsuitable for certain types of applications.(such as expressing properties of non-deterministic programs). In this paper we introduce the new temporal logic programming language Cactus, which is based on a branching notion of time. In Cactus, the truth value of a predicate depends on a hidden time parameter which varies over a tree-like structure. As a result, Cactus can be used to express in ra natural way non-deterministic computations or generally algorithms that involve the manipulation of tree data structures. Moreover, Cactus appears to be appropriate as the target language for compilers or program transformers. Cactus programs can be executed using BSLD resolution, a proof procedure based on the notion of canonical temporal atoms/clauses. (C) 1999 Elsevier Science Ltd. All rights reserved.
temporalprogramming languages are recognized as natural and expressive formalisms for describing dynamic systems. However, most such languages are based on linear flow of time, a fact that makes them unsuitable for c...
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ISBN:
(纸本)3540630953
temporalprogramming languages are recognized as natural and expressive formalisms for describing dynamic systems. However, most such languages are based on linear flow of time, a fact that makes them unsuitable for certain types of applications. In this paper we introduce the new temporal logic programming language Cactus, which is based on a branching notion of time. In Cactus, the truth value of a predicate depends on a hidden time parameter which has a tree-like structure. As a result, Cactus appears to be especially appropriate for expressing non-deterministic computations or generally algorithms that involve the manipulation of tree data structures.
The complexity of the satisfiability problem for 2 Horn fragments in propositional linear-time temporallogic is investigated. The first one contains 2 temporal connectives - eventuality and always only - and the 2nd...
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The complexity of the satisfiability problem for 2 Horn fragments in propositional linear-time temporallogic is investigated. The first one contains 2 temporal connectives - eventuality and always only - and the 2nd one contains an additional next-time connective. It has been shown that the satisfiability problem for linear-time temporallogic whose temporal connectives include eventuality and always only is NP-complete and is PSPACE-complete if additional next-time connective is permitted, according to Sistla and Clarke (1985). It is shown that the complexity of the satisfiability problem remains unchanged even if the input is restricted to temporal Horn formulas. In other words, if the next-time connective is not allowed to occur in temporal Horn formulas, the problem is NP-complete; otherwise, it is PSPACE-complete.
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