context: It is unlikely that Lily is a frog. It is impossible that John dropped the milk. It is probable that Brian is yellow.
hypothesis: It is certain that 'John dropped the milk and Lily is a frog'.
valid_hypothesis: It is impossible that 'John dropped the milk and Lily is a frog'.
invalid_hypothesis: It is certain that 'John dropped the milk and Lily is a frog'.
problog: 
    and(A,B) :- A,B.
    or(A,B) :- A;B.
    nand(A,B) :- not(and(A,B)).
    nor(A,B) :- not(or(A,B)).
    xor(A,B) :- or(A,B), nand(A,B).
  
    %hop0
    0.2::factA.
    0.0::factB.
    0.7::factC.
    
  
    %hop2
    conclusion:-and(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'John dropped the milk and Lily is a frog'.