有没有一种方法来创建一个for循环在C只有两个前pressions？

我碰到这在C标准文本来了，任何版本我能找到C99 C11或在§6.8.5：

I came across this in the C standard text, any version I can find for C99 or C11, at §6.8.5 :

iteration-statement:
  while ( expression ) statement
  do statement while ( expression ) ;
  for ( expression ; expression ; expression ) statement
  for ( declaration expression ;  expression ) statement

第四个项目在这里似乎是一个为只有一个分号，我没有看到这种语法其他任何地方的任何引用。任何人都可以在这里解释我缺少什么？

The fourth item here seems to be a for with only one semicolon, and I don't see any reference to this syntax anywhere else. Can anyone here explain what am I missing?