ACKNOWLEDGEMENTS

I am grateful to Ray Solomonoff, Peter Dayan, Mike Mozer, Don Matthis, Clayton McMillan, and various NIPS*94 participants, for valuable comments/discussions on the first version of [32]. Many thanks to Sepp Hochreiter, Gerhard Weiß, Martin Eldracher, Margit Kinder, and Daniel Prelinger, for critical remarks on earlier drafts, and to Leslie Kaelbling, David Cohn, Tommi Jaakkola, and Andy Barto, for useful comments on later versions. Also, thanks to Marco Dorigo, Luca Gambardella, Rafal Salustowicz, Cristina Versino, and Marco Wiering, for hepful remarks on [34]. I am particularly indebted to Mark Ring for extensive and constructive criticism. The recent collaboration with Jieyu Zhao was supported by SNF grant 21-43'417.95 ``Incremental Self-Improvement'' and SNF grant 2100-49'144.96 ``Long Short-Term Memory''.