belly up to vs converge

belly up to

converge

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

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

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

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