Joachim Niehren

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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)
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)
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)
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)
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)
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)