congruent vs extensional

congruent

adj
  • Harmonious. 

  • Satisfying a congruence relation. 

  • Having a difference divisible by a modulus. 

  • Coinciding exactly when superimposed. 

  • Corresponding in character; congruous 

extensional

adj
  • Having great extent. 

  • Of or pertaining to extension. 

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