【摘要】 本文讨论了通常程序设计语言的语义理解问题且提出了若干定义和概念，进而又论述了在不同层次上的等价性，从而为程序的转换和替代建立理论依据。本文还分析了程序设计语言及其源程序中的语境问题并提出了若干概念和定义，为软件移植性等的量化刻划提供帮助。更多还原

【Abstract】 In this paper, semantic nuderstanding of programming languages is discussed, some definitions and conceptions are presented, equality in different levels is analyzed, and the theoretical criterions is established for conversion and replacement of programs.And in this paper, languageenvironment (context) is analyzed and several conceptions are introduced.更多还原