introduce vs invalidate

introduce

verb
  • To make (something or someone) known by formal announcement or recommendation. 

  • To cause (someone) to be acquainted (with someone else). 

  • To add (something) to a system, a mixture, or a container. 

  • To bring (something) into practice. 

invalidate

verb
  • To make or declare (an argument, statement, or theory) unsound or erroneous; disprove. 

  • To make invalid. Especially applied to contract law. 

  • To render invalid; discredit. 

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