soundness vs treachery

soundness

noun
  • The result or product of being sound. 

  • The property (of an argument) of not only being valid, but also of having true premises. 

  • The property of a logical theory that whenever a wff is a theorem then it must also be valid. Symbolically, letting T represent a theory within logic L, this can be represented as the property that whenever T⊢𝜙 is true, then T vDash 𝜙 must also be true, for any wff φ of logic L. 

  • The state or quality of being sound. 

treachery

noun
  • An act or instance of treachery. 

  • Treason. 

  • Deliberate, often calculated, disregard for trust or faith. 

  • The act of violating the confidence of another, usually for personal gain. 

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