Berthe Y. Choueiry Yumi Iwasaki Sheila A. McIlraith Towards a practical theory of reformulation for reasoning about physical systems. 145-204 2005 162 Artif. Intell. 1-2 http://dx.doi.org/10.1016/j.artint.2004.01.004 db/journals/ai/ai162.html#ChoueiryIM05