On the Power of Deterministic Transitive Closures
نویسندگان
چکیده
We show that transitive closure logic (FO + TC) is strictly more powerful than deterministic transitive closure logic (FO + DTC) on nite (unordered) structures. In fact, on certain classes of graphs, such as hypercubes or regular graphs of large degree and girth, every DTC-query is bounded and therefore rst order expressible. On the other hand there are simple (FO + pos TC) queries on these classes that cannot be deened by rst order formulae.
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ورودعنوان ژورنال:
- Inf. Comput.
دوره 119 شماره
صفحات -
تاریخ انتشار 1995