extensional vs pertinent

extensional

adj
  • Of or pertaining to extension. 

  • Having great extent. 

pertinent

adj
  • Important with regard to (a subject or matter); pertaining; relevant. 

noun
  • A right that attaches to land, in Scots law. 

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