title: Infer incomplete rules
body: <p>How can I infer rules with incomplete facts as input?</p>
  
  <p>For example, I only has X eat flies as input:
    - {cf(croaks) 1.0}, {cf(eats flies) 1.0}, {cf(a frog) 1.0}
    - If X 'croaks' and X 'eats flies' Then X is 'a frog' {cf 1.0} </p>
  
  <ul>
  <li>If X is 'a frog' Then X is 'green' {cf 1.0}</li>
  </ul>
  
  <p>How can I infer X is green with some percentage accuracy?</p>