accede vs controvert

accede

verb
  • To agree or assent to a proposal or a view; to give way. 

  • To become a party to an agreement or a treaty. 

  • To come to an office, state or dignity; to attain, assume (a position). 

controvert

verb
  • To argue against (something or someone); to contradict, to deny. 

  • To dispute, to argue about (something). 

  • To be involved or engaged in controversy; to argue. 

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