context: It is unlikely that Sandra is in the kitchen. It is improbable that Greg is gray. We doubt that Bernhard is green.
hypothesis: It is probably not the case that either 'Bernhard is green' or 'Sandra is in the kitchen' but not both.
valid_hypothesis: It is probably not the case that either 'Bernhard is green' or 'Sandra is in the kitchen' but not both.
invalid_hypothesis: It is probable that either 'Bernhard is green' or 'Sandra is in the kitchen' 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
    0.2::factA.
    0.1::factB.
    0.2::factC.
    
  
    %hop2
    conclusion:-xor(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Bernhard is green' or 'Sandra is in the kitchen' but not both.