counterwork vs invalidate

counterwork

verb
  • To work in opposition to; to counteract. 

invalidate

verb
  • To render invalid; discredit. 

  • To make invalid. Especially applied to contract law. 

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

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