context: There is a better than even chance that John moved to the garden. It is probably not the case that Bernhard is yellow. Chances are about even that Jeff went to the bedroom.
hypothesis: It is highly unlikely that either 'Bernhard is yellow' or 'John moved to the garden' but not both.
valid_hypothesis: There is a better than even chance that either 'Bernhard is yellow' or 'John moved to the garden' but not both.
invalid_hypothesis: It is highly unlikely that either 'Bernhard is yellow' or 'John moved to the garden' 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.
    0.25::factB.
    0.5::factC.
    
  
    %hop2
    conclusion:-xor(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Bernhard is yellow' or 'John moved to the garden' but not both.