00273nam a2200109 a 450000500170000002000150001708200140003210000190004624500410006526000350010630000220014120251203090959.0 a0415023181 a160,bwol aWolfram, Sybil aPhilosophical logic: an introduction aLoNew Delhion" Routledgec1989 axiv,290p.c23 cm.