In this lecture we will start the transition from C0 to C. In some ways, the lecture is therefore about knowledge rather than principles. The underlying issue that we are trying to solve in this lecture is nevertheless a deep one: how can a language support generic implementations of data structures that accomodate data elements of different types. The name polymorphism derives from the fact th...

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.

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...

We introduce a natural extension of collapsible pushdown systems called annotated pushdown systems that replaces collapse links with stack annotations. We believe this new model has many advantages. We present a saturation method for global backwards reachability analysis of these models that can also be used to analyse collapsible pushdown systems. Beginning with an automaton representing a se...

We describe a general method for deciding bisimilarity for pairs of processes where one process has finitely many states. We apply this method to pushdown processes and to PA processes. We also demonstrate that the mentioned problem is undecidable for ‘state-extended’ PA processes.