To define presupposition
too sensitive to contextual factors (to be thought of as semantic in the narrow sense)
follow-up questions: How sensitive it is? What are those ''contextual factors?a focal area of linguistic theory during 1969-76 against generativismtechnical concept < ordinary language term = any kind of background assumption against an action or something makes senserestricted to certain pragamatic inferences or assumptions that seem at least to be built into linguistic expression and which can be isolated using specific linguistic tests (esp. constancy under negation) 这段话前面基本说了等于没说，constancy under negation才是重点。Frege 1892Russell 1905Strawson 1950
参考：Jef Verschueren. Understanding Pragmatics
Lots of deixis! seems no verbs?
p. 27 existential presuppositions
My interests:
How is topic/comment related to presupposition?Does the presupposition of the same sentence (perhaps same in terms of its ‘literal meaning’) varies according to cultures or contexts?Different types of deixis
eg. Stop being lazy vs. 劝君莫惜金缕衣，劝君惜取少年时。
