Natural deduction
Natural deduction
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DOI：
10.1007/978-0-230-00605-8_4
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
R. Zach
中科院分区：
文献类型：
--
作者：
P. Mancosu;S. Galvan;R. Zach
在前一章中，我们讨论了命题的真值，也讨论了命题形式之间的关系，即等价和语义蕴涵，它们可以用真值来定义。在这一章中，我们将看一看我们如何从一组已知的命题（称为前提）论证到得到一个进一步的命题（称为结论）。我们可以用很多这样的方法来证明一个论点，不是所有的方法在逻辑上都是可以接受的。考虑下面的例子。
In the previous chapter, we have been concerned with truth values of propositions, and also with relationships between propositional forms, namely equivalence and semantic entailment, which can be defined in terms of truth values. In this chapter we shall be looking at how we can argue from a given set of propositions known as premisses to obtain a further proposition known as the conclusion. There are many such ways in which we can justify an argument, not all of which are acceptable in logic. Consider the following example.