6Kempson,R.:Presupposition and the delimitation of semantics.London:Cambridge University Press,1975.
7Morris,C:Foundations of the theory of signs.In Neurath,O.,O.Carnap International Encyclopedia of Unified Science,Chicago:University of Chicago Press,1938.
8Stephen C Levinson:pragmatics.北京:外语教学与研究出版社,2001.11.