context: It is certain that Julius is a swan. Chances are slight that John moved to the garden. There is a better than even chance that Greg is a rhino.
hypothesis: There is a very good chance that 'John moved to the garden and Julius is a swan'.
valid_hypothesis: Chances are slight that 'John moved to the garden and Julius is a swan'.
invalid_hypothesis: There is a very good chance that 'John moved to the garden 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
    1.0::factA.
    0.1::factB.
    0.6::factC.
    
  
    %hop2
    conclusion:-and(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'John moved to the garden and Julius is a swan'.