implication vs obligation

implication

noun
  • The act of implicating. 

  • The state of being implicated. 

  • An implying, or that which is implied, but not expressed; an inference, or something which may fairly be understood, though not expressed in words. 

  • The connective in propositional calculus that, when joining two predicates A and B in that order, has the meaning "if A is true, then B is true". 

  • Logical consequence. 

  • A possible effect or result of a decision or action. 

obligation

noun
  • The act of binding oneself by a social, legal, or moral tie to someone. 

  • A social, legal, or moral requirement, duty, contract, or promise that compels someone to follow or avoid a particular course of action. 

  • A course of action imposed by society, law, or conscience by which someone is bound or restricted. 

  • A legal agreement stipulating a specified action or forbearance by a party to the agreement; the document containing such agreement. 

  • The fact of being obliged to, that is, grateful for, something. 

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