converge vs link up

converge

verb
  • (said of two or more entities) To approach each other; to get closer and closer. 

  • (said of a sequence or series) To have a (finite, proper) limit. 

  • (said of an iterative process) To reach a stable end point. 

link up

verb
  • To become linked or joined together. 

  • To link or join together. 

  • To meet with someone. 

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