formal parameter vs subject matter

formal parameter

noun
  • An abstract representation, typically including a name and a type, of a parameter expected to be passed to a method or function. 

subject matter

noun
  • The matter or thought presented for consideration in some statement or discussion; that which is made the object of thought or study. 

How often have the words formal parameter and subject matter occurred in a corpus of books? (source: Google Ngram Viewer )