context: Chances are about even that Bill went to the office. It is probably not the case that John left the apple. It is improbable that Brian is white.
hypothesis: It is improbable that 'John left the apple and Bill went to the office'.
valid_hypothesis: It is improbable that 'John left the apple and Bill went to the office'.
invalid_hypothesis: We believe that 'John left the apple and Bill went to the office'.
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
    0.5::factA.
    0.25::factB.
    0.1::factC.
    
  
    %hop2
    conclusion:-and(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'John left the apple and Bill went to the office'.