discussion vs rheme

discussion

noun
  • Text giving further detail on a subject. 

  • Conversation or debate concerning a particular topic. 

rheme

noun
  • The part of a sentence that provides new information regarding the current theme. 

  • A sign that represents its object in respect of quality and so, in its signified interpretant, is represented as a character or mark; sumisign. 

How often have the words discussion and rheme occurred in a corpus of books? (source: Google Ngram Viewer )