Computer Science – Artificial Intelligence
Scientific paper
2009-02-20
J. Symbolic Computation, 2009, 44:60--98
Computer Science
Artificial Intelligence
ii + 187 pages
Scientific paper
We study the combination of the following already known ideas for showing confluence of unconditional or conditional term rewriting systems into practically more useful confluence criteria for conditional systems: Our syntactical separation into constructor and non-constructor symbols, Huet's introduction and Toyama's generalization of parallel closedness for non-noetherian unconditional systems, the use of shallow confluence for proving confluence of noetherian and non-noetherian conditional systems, the idea that certain kinds of limited confluence can be assumed for checking the fulfilledness or infeasibility of the conditions of conditional critical pairs, and the idea that (when termination is given) only prime superpositions have to be considered and certain normalization restrictions can be applied for the substitutions fulfilling the conditions of conditional critical pairs. Besides combining and improving already known methods, we present the following new ideas and results: We strengthen the criterion for overlay joinable noetherian systems, and, by using the expressiveness of our syntactical separation into constructor and non-constructor symbols, we are able to present criteria for level confluence that are not criteria for shallow confluence actually and also able to weaken the severe requirement of normality (stiffened with left-linearity) in the criteria for shallow confluence of noetherian and non-noetherian conditional systems to the easily satisfied requirement of quasi-normality. Finally, the whole paper may also give a practically useful overview of the syntactical means for showing confluence of conditional term rewriting systems.
No associations
LandOfFree
Syntactic Confluence Criteria for Positive/Negative-Conditional Term Rewriting Systems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Syntactic Confluence Criteria for Positive/Negative-Conditional Term Rewriting Systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Syntactic Confluence Criteria for Positive/Negative-Conditional Term Rewriting Systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-671495