In this paper we study the problem of deciding boundedness of (recursive) regular path queries over views in data integration systems, that is, whether a query can be re-expressed without recursion. This problem becomes challenging when the views contain recursion, thereby potentially making recursion in the query uncessary. We define and solve two related problems of boundedness of regular pat...

Higher-order recursion schemes are systems of rewrite rules on typed non-terminal symbols, which can be used to define infinite trees. The Global Modal Mu-Calculus Model Checking Problem takes as input such a recursion scheme together with a modal μ-calculus sentence and asks for a finite representation of the set of nodes in the tree generated by the scheme at which the sentence holds. Using a...

Compositions of command statements, branching, iteration and recursion are primarily used in high-level programming languages to devise algorithms and obtain structured control flow. These structuring building blocks may also be instrumental for describing real-life systems in analysis and design methodologies at any complexity level. While composition and branching are incorporated into most p...

Results are presented which show precise ways in which recursion rests on very simple computational bases which do not support diagonalization. A method based on recursion and making no use of diagonalization is given for proving lower bounds on computational complexity. Thus the intractability of computational problems such as Presburger arithmetic does not depend on diagonalization. This rese...

We identify the Baker-Campbell-Hausdorff recursion driven by a weight λ=1 Rota-Baxter operator with Magnus expansion relative to post-Lie structure naturally associated corresponding algebra. Post-Lie and BCH-recursion are reviewed before proof of main result.

This is the first of a series of papers on complexity-theoretic algebra. We carne to the subject as follows. In 1975 Metakides and Nerode [15] initiated the systematic study of recursion-theoretic algebra. The motivation was to establish the recursive content of mathematical constructions. The novelty was the use of the finite injury priority method from recursion theory as a uniform tool to me...