Completeness and decidability of three logics of counterfactual conditionals1
Completeness and decidability of three logics of counterfactual conditionals1
复制标题
反事实条件句的三种逻辑的完整性和可判定性1
DOI：
--
复制
发表时间：
2008
期刊：
影响因子：
--
通讯作者：
D. Lewis
中科院分区：
文献类型：
--
作者：
D. Lewis
句子Q]0-Ty的意思大致是，y在Q]所在的某些可能世界中成立：那些与我们的实际世界最接近的可能世界。我们可以通过假设一个函数f来最直接地捕捉到这一意图，该函数为任何句子9和世界i选择一个世界集合f(v，i)，该集合被认为是Q]所在的世界中与i最相似的世界集合。但这种做法可能会遭到反对。正如没有大于1的实数最接近于0一样，Q]所在的世界中也可能没有一个最接近于i，也可能对它们中的每一个，都有一个更接近的世界。为了解决这一困难，我们可以引入世界之间相似度的概念，并将q]0-ty视为意味着，除非没有v所在的世界与我们的实际世界有任何程度的相似，否则存在与我们的实际世界一定程度的相似
A sentence Q] 0-t y is intended to mean, roughly, that y holds in certain of the possible worlds in which Q] holds: those of them that are most closely similar to our actual world. We could capture this intention most straightforwardly by positing a function f which selects, for any sentence 9 and world i, a set f(v, i) of worlds regarded as the set of worlds most closely similar to i out of the worlds in which Q] holds. But this approach is open to objection. Just as no real number greater than 1 is closest to 0, so it may be that none of the worlds in which Q] holds is most closely similar to i. It may be that for each of them, there is another still closer. To meet this difficulty, we could introduce the notion of degrees of similarity between worlds, and take Q] 0-t y to mean that, unless no worlds in which v holds are similar to any degree to our actual world, there is some degree of similarity to our actual world within which there are