Van Wijngaarden文法、变形和K-ary恶意软件
Van Wijngaarden grammars, metamorphism and K-ary malwares
摘要：
语法用于描述句子结构，这要归功于一些规则集，这些规则集取决于语法类型。诺姆·乔姆斯基（Noam Chomsky）对语法进行了分类，并将其分为四种著名的类型。然而，还有其他类型的语法，不完全符合乔姆斯基的分类，如两级语法。正如它们的名字所暗示的，这些语法背后的主要思想是它们由两个语法组成。范·维恩加登文法尤其是这样的文法。它们的力量（表现力）是有趣的，在某些假设下，它们可以与乔姆斯基分类中最强大的语法，即0型语法相同。另一个有趣的地方是它们的相对简洁性和可读性。Van Wijngaarden文法可以描述语言的静态和动态语义。因此，通过将它们用作生成引擎，可以生成可能无限的单词集，同时向我们保证它们都具有相同的语义。此外，他们可以描述K元码，通过描述代码的每个组件的语义。
英文摘要：
Grammars are used to describe sentences structure, thanks to some sets of rules, which depends on the grammar type. A classification of grammars has been made by Noam Chomsky, which led to four well-known types. Yet, there are other types of grammars, which do not exactly fit in Chomsky's classification, such as the two-level grammars. As their name suggests it, the main idea behind these grammars is that they are composed of two grammars. Van Wijngaarden grammars, particularly, are such grammars. They are interesting by their power (expressiveness), which can be the same, under some hypotheses, as the most powerful grammars of Chomsky's classification, i.e. Type 0 grammars. Another point of interest is their relative conciseness and readability. Van Wijngaarden grammars can describe static and dynamic semantic of a language. So, by using them as a generative engine, it is possible to generate a possibly infinite set of words, while assuring us that they all have the same semantic. Moreover, they can describe K-ary codes, by describing the semantic of each components of a code.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
