Sequentiality in orthogonal term rewriting systems
نویسندگان
چکیده
منابع مشابه
Optimal Normalization in Orthogonal Term Rewriting Systems
We design a normalizing strategy for orthogonal term rewriting systems (OTRSs), which is a generalization of the call-by-need strategy of Huet-L evy 4]. The redexes contracted in our strategy are essential in the sense that they have \descendants" under any reduction of a given term. There is an essential redex in any term not in normal form. We further show that contraction of the innermost es...
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In this paper we first study the difference between Weak Normalization (WN) and Strong Normalization (SN), in the framework of first order orthogonal rewriting systems. With the help of the Erasure Lemma we establish a Pumping Lemma, yielding information about exceptional terms, defined as terms that are WN but not SN. A corollary is that if an orthogonal TRS is WN, there are no cyclic reductio...
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We establish some fundamental facts for infinitary orthogonal term rewriting systems (OTRSs): for strongly convergent reductions we prove the Transfinite Parallel Moves Lemma and the Compressing Lemma. Strongness is necessary as shown by counterexamples. Normal forms (which we allow to be infinite) are unique, in contrast to ω-normal forms. Fair reductions result in ω-normal forms if they are c...
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ژورنال
عنوان ژورنال: Journal of Symbolic Computation
سال: 1991
ISSN: 0747-7171
DOI: 10.1016/s0747-7171(08)80124-1