title: What is the marginal probabilities formula used in CRF++?
body: <p>CRF++ says it can:</p>
  
  <p>"Can output marginal probabilities for all candidates" on its page: <a href="http://crfpp.sourceforge.net/" rel="nofollow">http://crfpp.sourceforge.net/</a></p>
  
  <p>But what's the notation of the formula that's used to find these probabilities, in  conditional random fields? </p>
  
  <p>Someone told me it's not simply <code>p(a|b)</code>, because conditional random fields use context from adjacent observations.</p>
  
  <p>What exactly are these marginal probabilities?</p>