build on vs condense

build on

verb
  • To add additional elements or components to (a framework, a concept, a device, etc.) in order to extend it. 

condense

verb
  • To be transformed from a gaseous state into a liquid state. 

  • To transform from a gaseous state into a liquid state via condensation. 

  • To concentrate toward the essence by making more close, compact, or dense, thereby decreasing size or volume. 

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