本标准体现在Std_logic_1164包声明和 Std_logic_1164包体以及本第1条文件。附录A中的信息是一个指南 并不是本标准的一部分，但建议用户使用此软件包的方式

This standard is embodied in the Std_logic_1164 package declaration and the semantics of the Std_logic_1164 package body along with this clause 1 documentation. The information annex A is a guide to users and is not part of this standard, but suggests ways in which one might use this package