colligation vs mergence

colligation

noun
  • A binding together. 

  • The formulation of a general hypothesis which seeks to connect two or more facts. 

  • The co-occurrence of syntactic categories, usually within a sentence. 

mergence

noun
  • The act of merging. 

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