PROLEG: An Implementation of the Presupposed Ultimate Fact Theory of Japanese Civil Code by PROLOG Technology. - Ken Satoh; Kento Asai; Takamune Kogawa; Masahiro Kubota; Megumi Nakamura; Yoshiaki Nishigai; Kei Shirakawa; Chiaki Takano (JSAI-isAI Workshops, 2010)