context: It is unlikely that Sandra left the milk. There is a very good chance that Mary went to the kitchen. Chances are about even that Bernhard is a rhino.
hypothesis: There is almost no chance that either 'Sandra left the milk' or 'Bernhard is a rhino' but not both.
valid_hypothesis: Chances are about even that either 'Sandra left the milk' or 'Bernhard is a rhino' but not both.
invalid_hypothesis: There is almost no chance that either 'Sandra left the milk' or 'Bernhard is a rhino' 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.
    0.8::factB.
    0.5::factC.
    
  
    %hop2
    conclusion:-xor(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Sandra left the milk' or 'Bernhard is a rhino' but not both.