context: It is unlikely that Gertrude is a cat. Chances are about even that Bill went to the garden. There is almost no chance that Sandra left the milk.
hypothesis: Chances are about even that 'Sandra left the milk' or 'Bill went to the garden' or both.
valid_hypothesis: Chances are about even that 'Sandra left the milk' or 'Bill went to the garden' or both.
invalid_hypothesis: There is almost no chance that 'Sandra left the milk' or 'Bill went to the garden' or both.
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.
    0.5::factB.
    0.02::factC.
    
  
    %hop2
    conclusion:-or(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Sandra left the milk' or 'Bill went to the garden' or both.