Garbage collectors are an important part of many modern language runtimes. Essentially all tools for developing and debugging programs using garbage collection assume the correctness of the collector, and therefore provide no means for detecting garbage collector errors. As a result it is especially important that garbage collector implementations be free of errors. This goal is even more chall...

In this paper we address the problem of solving parity games over the configuration graphs of bounded phase multi-pushdown systems. A non-elementary decision procedure was proposed for this problem by A. Seth. In this paper, we provide a simple and inductive construction to solve this problem. We also prove a non-elementary lower-bound, answering a question posed by A.Seth.

We introduce and investigate input-driven stack automata, which are a generalization of input-driven pushdown automata that recently became popular under the name visibly pushdown automata. Basically, the idea is that the input letters uniquely determine the operations on the pushdown store. This can nicely be generalized to stack automata by further types of input letters which are responsible...

We propose a new extension of higher-order pushdown automata, which allows to use an infinite alphabet. The new automata recognize languages of data words (instead of normal words), which beside each its letter from a finite alphabet have a data value from an infinite alphabet. Those data values can be loaded to the stack of the automaton, and later compared with some farther data values on the...

The notions of generation, production, synthesis etc. are analyzed, with the conclusion, that the description of a natural language should have ~ a creative and a transductive part. As a system meeting the principal known conditions, a sequence of pushdown store transducers, interpreted as a strat~f~cational language descrlption~is proposed.

Although the native (tree-like) storage of XML data becomes more and more important there will be an enduring demand to manage XML data in its textual representation, for instance in relational structures or file systems. XML data has to be wellformed by definition and additionally, in many cases, it has to be valid according to a given XML schema. Because the XML column types are often derived...

This paper introduces and discusses pure multi-pushdown automata that remove symbols from their pushdowns only by performing complete-pushdown pops. During this operation, the entire pushdown is compared with a prefix of the input, and if they match, the pushdown is completely emptied and the input is advanced by the prefix. The paper proves that these automata define an infinite hierarchy of l...

Article history: Received 9 July 2013 Available online 28 April 2014

In a recent paper [19, 20] Serre has presented some decidable winning conditions ΩA1B...BAnBAn+1 of arbitrarily high finite Borel complexity for games on finite graphs or on pushdown graphs. We answer in this paper several questions which were raised by Serre in [19, 20]. We study classes Cn(A), defined in [20], and show that these classes are included in the class of non-ambiguous context free...