antecedent vs prefatory

antecedent

adj
  • Presumptive. 

  • Earlier, either in time or in order. 

noun
  • The first term of a ratio, i.e. the term a in the ratio a:b, the other being the consequent. 

  • An ancestor. 

  • Previous principles, conduct, history, etc. 

  • Any thing that precedes another thing, especially the cause of the second thing. 

  • A word, phrase or clause referred to by a pronoun. 

  • The first of two subsets of a sequent, consisting of all the sequent's formulae which are valuated as true. 

  • The conditional part of a hypothetical proposition, i.e. p→q, where p is the antecedent, and q is the consequent. 

prefatory

adj
  • Serving as a preface or prelude; introductory, preliminary. 

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