context: We believe that Sandra left the milk. It is probably not the case that Julius is a swan. There is little chance that Mary picked up the milk.
hypothesis: It is highly likely that 'Mary picked up the milk and Julius is a swan'.
valid_hypothesis: There is almost no chance that 'Mary picked up the milk and Julius is a swan'.
invalid_hypothesis: It is highly likely that 'Mary picked up the milk and Julius is a swan'.
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
    0.75::factA.
    0.25::factB.
    0.1::factC.
    
  
    %hop2
    conclusion:-and(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary picked up the milk and Julius is a swan'.