© 2001 by Oxford University Press
Free-variable tableaux for monotonic preorders
Departamento de Sistemas Informáticos y Programación, Fac. de Informática, Univ. Complutense de Madrid, 28040 - Madrid, Spain E-mail: pjmartin@sip.ucm.es; agav@sip.ucm.es
Monotonic preorders are integrated into tableaux using a simultaneous rigid unification calculus. For the case where monotonicity is not considered, a sound, complete and terminating calculus is defined and subsequently refined by using rewrite techniques. For the monotonic case, a sound and existentially complete calculus is presented which avoids the computation of some naive solutions.
Key Words: Monotonic preorders, rigid unification, free-variable tableaux