negation vs nonpositive

negation

noun
  • The act of negating something. 

  • A proposition which is the contradictory of another proposition and which can be obtained from that other proposition by the appropriately placed addition/insertion of the word "not". (Or, in symbolic logic, by prepending that proposition with the symbol for the logical operator "not".) 

  • A denial or contradiction. 

  • The logical operation which obtains such (negated) propositions. 

nonpositive

noun
  • Any value that is not positive. 

adj
  • Not positive; either zero or negative. 

  • Not positive. 

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