context: There is a very good chance that Greg is white. There is almost no chance that Mary went to the office. It is unlikely that Sandra took the milk.
hypothesis: There is almost no chance that 'Greg is white and Mary went to the office'.
valid_hypothesis: There is almost no chance that 'Greg is white and Mary went to the office'.
invalid_hypothesis: We believe that 'Greg is white and Mary 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
    0.8::factA.
    0.02::factB.
    0.2::factC.
    
  
    %hop2
    conclusion:-and(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Greg is white and Mary went to the office'.