context: It is impossible that Greg is yellow. It is probably not the case that Gertrude is a mouse. There is almost no chance that Julius is green.
hypothesis: It is impossible that 'Julius is green and Gertrude is a mouse'.
valid_hypothesis: It is impossible that 'Julius is green and Gertrude is a mouse'.
invalid_hypothesis: It is almost certain that 'Julius is green and Gertrude is a mouse'.
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
    0.0::factA.
    0.25::factB.
    0.02::factC.
    
  
    %hop2
    conclusion:-and(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Julius is green and Gertrude is a mouse'.