Computer Science – Logic in Computer Science
Scientific paper
2007-06-26
Dans Proceedings of the 25th Annual Symposium on the Theoretical Aspects of Computer Science - STACS 2008, Bordeaux : France (
Computer Science
Logic in Computer Science
Revised version contributed to STACS 2008
Scientific paper
We compare the expressiveness of two extensions of monadic second-order logic (MSO) over the class of finite structures. The first, counting monadic second-order logic (CMSO), extends MSO with first-order modulo-counting quantifiers, allowing the expression of queries like ``the number of elements in the structure is even''. The second extension allows the use of an additional binary predicate, not contained in the signature of the queried structure, that must be interpreted as an arbitrary linear order on its universe, obtaining order-invariant MSO. While it is straightforward that every CMSO formula can be translated into an equivalent order-invariant MSO formula, the converse had not yet been settled. Courcelle showed that for restricted classes of structures both order-invariant MSO and CMSO are equally expressive, but conjectured that, in general, order-invariant MSO is stronger than CMSO. We affirm this conjecture by presenting a class of structures that is order-invariantly definable in MSO but not definable in CMSO.
Ganzow Tobias
Rubin Sasha
No associations
LandOfFree
Order-Invariant MSO is Stronger than Counting MSO in the Finite 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 Order-Invariant MSO is Stronger than Counting MSO in the Finite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Order-Invariant MSO is Stronger than Counting MSO in the Finite will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-505308