as in vs tetra- used for substitutions of four complex rather than simple units

as in

adv
  • In the sense of. 

  • Used other than figuratively or idiomatically: see as, in. 

tetra- used for substitutions of four complex rather than simple units

How often have the words as in and tetra- used for substitutions of four complex rather than simple units occurred in a corpus of books? (source: Google Ngram Viewer )