context: We believe that Julius is gray. It is highly unlikely that Mary got the milk. It is highly unlikely that Gertrude is a mouse.
hypothesis: Chances are slight that 'Gertrude is a mouse' or 'Julius is gray' or both.
valid_hypothesis: We believe that 'Gertrude is a mouse' or 'Julius is gray' or both.
invalid_hypothesis: Chances are slight that 'Gertrude is a mouse' or 'Julius is gray' 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
    0.75::factA.
    0.05::factB.
    0.05::factC.
    
  
    %hop2
    conclusion:-or(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Gertrude is a mouse' or 'Julius is gray' or both.