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- Markus Egg, Alexander Koller, Joachim Niehren
- Journal of Logic, Language and Information
- 2001

This paper presents the Constraint Language for Lambda Structures (CLLS), a first-order language for semantic underspecification that conservatively extends dominance constraints. It is interpreted over lambda structures, tree-like structures that encode λ-terms. Based on CLLS, we present an underspecified, uniform analysis of scope, ellipsis, anaphora, and… (More)

- Céline Kuttler, Joachim Niehren
- Trans. Computational Systems Biology
- 2006

We propose to model the dynamics of gene regulatory networks as concurrent processes in the stochastic pi calculus. As a first case study, we show how to express the control of transcription initiation at the lambda switch, a prototypical example where cooperative enhancement is crucial. This requires concurrent programming techniques that are new to… (More)

- Wim Martens, Joachim Niehren
- J. Comput. Syst. Sci.
- 2007

Automata for unranked trees form a foundation for XML schemas, querying and pattern languages. We study the problem of efficiently minimizing such automata. First, we study unranked tree automata that are standard in database theory, assuming bottom-up determinism and that horizontal recursion is represented by deterministic finite automata. We show that… (More)

- Ernst Althaus, Denys Duchier, Alexander Koller, Kurt Mehlhorn, Joachim Niehren, Sven Thiel
- J. Algorithms
- 2003

Dominance constraints are logical descriptions of trees that are widely used in computational linguistics. Their general satisfiability problem is known to be NP-complete. Here we identify normal dominance constraints and present an efficient graph algorithm for testing their satisfiablity in deterministic polynomial time. Previously, no polynomial time… (More)

We define a back-and-forth translation between Hole Semantics and dominance constraints, two formalisms used in underspecified semantics. There are fundamental differences between the two, but we show that they disappear on practically useful descriptions. Our encoding bridges a gap between two underspecification formalisms, and speeds up the processing of… (More)

- Julien Carme, Joachim Niehren, Marc Tommasi
- RTA
- 2004

The problem of selecting nodes in unranked trees is the most basic querying problem for XML. We propose stepwise tree automata for querying unranked trees. Stepwise tree automata can express the same monadic queries as monadic Datalog and monadic second-order logic. We prove this result by reduction to the ranked case, via a new systematic correspondence… (More)

- Alexander Koller, Joachim Niehren, Ralf Treinen
- LACL
- 1998

Dominance constraints for nite tree structures are widely used in several areas of computational linguistics including syntax, semantics, and discourse. In this paper, we investigate algorithmic and complexity questions for dominance constraints and their rst-order theory. We present two NP algorithms for solving dominance constraints, which have been… (More)

- Joachim Niehren, Jan Schwinghammer, Gert Smolka
- Theor. Comput. Sci.
- 2005

We introdu e a new on urrent lambda al ulus with futures, (fut), to model the operational semanti s of onurrent extensions of ML. (fut) an safely express a variety of high-level on urren y onstru ts, in luding hannels, semaphores, or ports. Safe implementations of these onstru ts in (fut) annot be orrupted in any well-typed ontext. We prove safety on basis… (More)

We propose React(C ), an expressive programming language for stochastic modeling and simulation in systems biology that is based on biochemical reactions with constraints. We prove that React(C ) can express the stochastic π-calculus, in contrast to previous rule-based programming languages, and further illustrate the high expressiveness of React(C ). We… (More)

- Julien Carme, Aurélien Lemay, Joachim Niehren
- ICGI
- 2004

A base problem in Web information extraction is to find appropriate queries for informative nodes in trees. We propose to learn queries for nodes in trees automatically from examples. We introduce node selecting tree transducer (NSTT) and show how to induce deterministic NSTTs in polynomial time from completely annotated examples. We have implemented… (More)