notation vs opinions

notation

noun
  • This section lists all algebraic notation used in this book. (Using notations would be incorrect). 

  • The act, process, method, or an instance of representing by a system or set of marks, signs, figures, or characters. 

  • A specific note or piece of information written in such a notation. 

  • A system of characters, symbols, or abbreviated expressions used in an art or science or in mathematics or logic to express technical facts or quantities. 

opinions

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