A presupposition is background belief, relating to an utterance , that
The utterance John regrets that he stopped doing linguistics before he left Cambridge has the following presuppositions:
Talmy, Leonard. 1985. "Lexicalization patterns: Semantic structure in lexical forms." In Shopen 1985d
Levinson, Stephen C. 1983.Pragmatics. Cambridge, England: Cambridge University.
Crystal, David. 1980.A first dictionary of linguistics and phonetics. Boulder, CO: Westview.
Caton, Charles E. 1981. "Stalnaker on pragmatic presupposition." In Cole, P. 1981 83–100.