M. Teresa Escrig Lledó Museros Cabedo Julio Pacheco Francisco Toledo Several Models on Qualitative Motion as instances of the CSP. 55-71 2002 17 Inteligencia Artificial, Revista Iberoamericana de Inteligencia Artificial http://tornado.dia.fi.upm.es/caepia/numeros/17/escrig.pdf db/journals/aepia/aepia17.html#EscrigCPT02