@conference {RicKor-DSEG-2001,
	title = {A dynamic setup for elementary geometry},
	booktitle = {Proceedings of MTCM 2000},
	year = {2001},
	publisher = {Springer-Verlag},
	organization = {Springer-Verlag},
	abstract = {<p>
	In this article we survey the theoretical background that is required to build a consistent and continuous setup of dynamic elementary geometry. Unlike in static elementary geometry in dynamic elementary geometry the elements of a construction are allowed to move around as long as the geometric constraints intended by the construction are not violated. A typical problem in such a scenario is to resolve ambiguous situations that arise from geometric operations like intersecting a circle and a line. After introducing a formal framework for dealing with dynamic geometric constructions, we will demonstrate that a suitable resolution of these ambiguities requires the consideration of complex projective spaces. We will discuss several aspects where one can benefit from such a rather general approach. Finally, we will sketch some proofs that show that several fundamental algorithmic problems arising in such a context are NP-hard or even harder.</p>
},
	keywords = {refereed},
	url = {http://kortenkamps.net/papers/2001/35\_DynamicSetup.pdf},
	author = {Richter-Gebert, J{\"u}rgen and Kortenkamp, Ulrich}
}
