Search methods provide short and human readable proofs, i.e. with few algebra, of most of the theorems of the Euclidean plane. They are less succesful and convincing for incidence theorems of projective geometry, which has received less attention up to now. This is due to the fact that basic notions, like angles and distances, which are relevant for Euclidean geometry, are no more relevant for ...

Intracellular signalling often employs excitable stores of calcium coupled by di usion. We describe here the ability of such a mechanism to generate a complete set of logic gates required for computation, as well as how they can act as coincidence detectors for biological signals. c © 2004 Elsevier B.V. All rights reserved.

This study presents a detailed morphological analysis of a new species belonging to the blind trilobite Trimerocephalus McCoy, 1849, T. chopini n. sp., based on exceptionally well preserved articulated specimens from the Late Devonian (Early Famennian) of the Holy Cross Mountains in central Poland. The occurrence of this taxon in Kowala Quarry near Kielce has been reported previously, with spec...

The expression of contracts in computer readable form, and the development of automated tests for completeness and well-formedness of contracts, has opened the door to significant advances in automating contract negotiations. To meet the needs of automation, such negotiations must follow explicitly specified message-exchange protocols. But to meet the needs of the negotiating parties, these pro...

We present IREP++, a rule learning algorithm similar to RIPPER and IREP. Like these other algorithms IREP++ produces accurate, human readable rules from noisy data sets. However IREP++ is able to produce such rule sets more quickly and can often express the target concept with fewer rules and fewer literals per rule resulting in a concept description that is easier for humans to understand. The...

This paper introduces a new cellular automaton model of excitable media with improved treatments of (1) diiusion and wave propagation, and (2) slow dynamics of the recovery variable. The automaton is both computationally eecient and faithful to the underlying partial diierential equations.

Wave propagation governed by reaction-diffusion equations in homogeneous media has been studied extensively, and initiation and propagation are well understood in scalar equations such as Fisher’s equation and the bistable equation. However, in many biological applications the medium is inhomogeneous, and in one space dimension a typical model is a series of cells, within each of which the dyna...

Propagation of pulses in myelinated fibers may be described by appropriate solutions of spatially discrete FitzHugh-Nagumo systems. In these systems, propagation failure may occur if either the coupling between nodes is not strong enough or the recovery is too fast. We give an asymptotic construction of pulses for spatially discrete FitzHugh-Nagumo systems which agrees well with numerical simul...

We formalize Simplified Boardgames language, which describes a subclass of arbitrary board games. The language structure is based on the regular expressions, which makes the rules easily machine-processable while keeping the rules concise and fairly human-readable.