@UNPUBLISHED{solovay-arthan-harrison, author = "Robert M. Solovay and R.D. Arthan and John Harrison", title = "Some new results on decidability for elementary algebra and geometry", note = "ArXiV preprint 0904.3482; submitted to Annals of Pure and Applied Logic. Available at {\url{http://arxiv.org/PS_cache/arxiv/pdf/0904/0904.3482v1.pdf}}", year = 2009}