context: It is certain that John moved to the garden. It is probably not the case that Mary got the football. It is probably the case that Winona is a wolf.
hypothesis: It is unlikely that either 'Mary got the football' or 'John moved to the garden' but not both.
valid_hypothesis: We believe that either 'Mary got the football' or 'John moved to the garden' but not both.
invalid_hypothesis: It is unlikely that either 'Mary got the football' 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
    1.0::factA.
    0.25::factB.
    0.7::factC.
    
  
    %hop2
    conclusion:-xor(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Mary got the football' or 'John moved to the garden' but not both.