Pushdown automaton

About: Pushdown automaton is a research topic. Over the lifetime, 1868 publications have been published within this topic receiving 35399 citations.

Conditional weighted pushdown systems and applications

Abstract: Pushdown systems are well understood as abstract models of programs with (recursive) procedures. Reps et al. recently extended pushdown systems into weighted pushdown systems, which serve as a generalized framework for solving certain kinds of meet-over-all-path problems in program analysis. In this paper, we extend weighted pushdown systems to conditional weighted pushdown systems, by further specifying conditions under which a pushdown transition rule can be applied, and show that model checking problems on conditional weighted pushdown systems can be reduced to those on weighted pushdown systems.There are wider applications of conditional weighted pushdown systems when analyzing programs with objected-oriented features, for which weighted pushdown systems is not precise enough under a direct application. As an example, we lift a stacking-based points-to analysis for Java designed in the framework of weighted pushdown systems to a more precise counterpart in the framework of conditional weighted pushdown systems. In addition to the fundamental context-sensitivity in terms of valid paths, the lifted points-to analysis algorithm further enjoys context-sensitivity with respect to objected-oriented features, including call graph construction, heap abstraction, and heap access. These context-sensitive properties are shown to be crucial to the analysis precision in practice.

On Deciding if Deterministic Rabin Language Is in Büchi Class

Abstract: In this paper we give a proof that it is decidable for a deterministic tree automaton on infinite trees with Rabin acceptance condition, if there exists an equivalent nondeterministic automaton with Buchi acceptance condition. In order to prove this we transform an arbitrary deterministic Rabin automaton to a certain canonical form. Using this canonical form we are able to say if there exists a Buchi automaton equivalent to the initial one. Moreover, if it is the case, the canonical form allows us also to find a respective Buchi automaton.

An Insertion into the Chomsky Hierarchy

Abstract: This review paper will report on some recent discoveries in the area of Formal Languages, chiefly by F. Otto, G. Buntrock and G. Niemann. These discoveries have pointed out certain break-throughs connected with the concept of growing context-sensitive languages, which originated in the 1980’s with a paper by E. Dahlhaus and M.K. Warmuth. One important result is that the deterministic growing context-sensitive languages turn out to be identical to an interesting family of formal languages definable in a certain way by confluent reduction systems.