Discourse Representation Theory
Discourse Representation Theory
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话语表征理论
DOI：
10.1007/bf00627482
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发表时间：
2012
影响因子：
1.1
通讯作者：
Daniel Bonevac
中科院分区：
文献类型：
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作者：
Daniel Bonevac
14世纪的逻辑学家，如伯利和布里丹指出，量词不仅表达术语之间的关系，而且还在话语中引入可以用回指法指代的项目。这引起的问题不是真值条件的问题，正如我们已经看到的那样--给出句子的一阶表示并不难，比如“一只动物在跑，它是一个人”或“每个拥有驴子的农民都在打它”--而是组合性的问题。换句话说，问题通常不是缺乏适当的真值条件，而是生成它们的规则管理方式。在亚里士多德的逻辑中，我们可以把“一个动物在奔跑”表示为“某个A是R”，但是这样我们就没有办法表明这个奔跑的动物是人，提出另一个直言命题也无济于事。在一阶逻辑中，类似地，我们可以将“动物正在奔跑”表示为Ax <$x（Ax <$Rx）。然而，这样做之后，我们无法再添加另一个公式来表示所讨论的x是一个人，在这两种情况下，我们必须做的是扩展原来的表示，写作“一些A是R和M”或“A x”（Ax <$Rx <$Mx）。既然回指出现在同一个句子中，我们也许可以写一些规则来要求这样做。但类似的回指也可以跨越不同的边界。布里丹的例子也可以简单地说是“一只动物在奔跑”。这是一个男人。此外，这些可以被介入的话语分开：“一个动物在奔跑。人们惊讶地看着。这是罕见的看到这样的景象在广场上，在人群中，在中午的热量。这是一个男人。这使得一个等待关闭第一个句子的表征，直到所有后来的回指都被收集起来的策略变得不可信。有时，问题是缺乏适当的真值条件。考虑一下这个话语：
Fourteenth-century logicians such as Burley and Buridan note that quantifiers not only express relations between terms but also introduce items in discourse that can be referred to anaphorically. The problem this raises is not one of truth conditions, as we have seen—it is not difficult to give first-order representations of sentences such as ‘an animal is running and it is a man’ or ‘Every farmer who owns a donkey beats it’— but rather of compositionality. The problem, in other words, is typically not a lack of appropriate truth conditions but a rule-governed way of generating them. In Aristotelian logic, we can represent ‘an animal is running’ as ‘Some A is R,’ but we then have no way of indicating that the running animal is a man. Appending another categorical proposition will not help. In first-order logic, similarly, we can represent ‘an animal is running’ as ∃x(Ax ∧ Rx). Having done that, however, we have no way of adding another formula representing that the x in question is a man. What we have to do in both cases is extend the original representation, writing ‘Some A is R and M’ or ∃x(Ax ∧ Rx ∧ Mx). Since the anaphora occurs within the same sentence, we could perhaps write rules requiring this. But similar anaphora can occur across sentential boundaries. Buridan’s example could just as easily have been ‘an animal is running. It is a man.’ These could moreover be separated by intervening discourse: ‘an animal is running. People look on in surprise. It is uncommon to see such a sight in the square, amidst the crowds, in the midday heat. It is a man.’ This makes a strategy of waiting to close off the representation of the first sentence until all later anaphors have been collected implausible. Sometimes, the problem is a lack of appropriate truth conditions. Consider this discourse: