Notice that the relationship between the rhetorical is and the grammatical is is basically the relationship between what Jakobson calls the "poetic function" and the "metalingual function."

注意下,修辞学上的is和语法中的is之间的关系,基本上就是雅各布森所说的,“诗功能“和“元语言功能“之间的关系“

耶鲁公开课 - 文学理论导论课程节选

Content is a function -or let me say practical language, the purpose, in other words, of communicating facts or of communicating at all, which we associate with practical language -is a function of poetic language.

他们认为，内容即是功能,实用语言的目的，就是交流，我们总是把交流和实用语言联系,但其实它也是诗歌语言的功能。

耶鲁公开课 - 文学理论导论课程节选