context: There is a better than even chance that Bernhard is a swan. It is probable that Julius is gray. It is improbable that John moved to the office.
hypothesis: There is almost no chance that either 'John moved to the office' or 'Julius is gray' but not both.
valid_hypothesis: It is probable that either 'John moved to the office' or 'Julius is gray' but not both.
invalid_hypothesis: There is almost no chance that either 'John moved to the office' or 'Julius is gray' but not 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
    0.6::factA.
    0.7::factB.
    0.1::factC.
    
  
    %hop2
    conclusion:-xor(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: Either 'John moved to the office' or 'Julius is gray' but not both.