context: It is probable that Daniel took the apple. It is highly unlikely that John moved to the garden. It is almost certain that Lily is a rhino.
hypothesis: We believe that either 'Lily is a rhino' or 'Daniel took the apple' but not both.
valid_hypothesis: It is probably not the case that either 'Lily is a rhino' or 'Daniel took the apple' but not both.
invalid_hypothesis: We believe that either 'Lily is a rhino' or 'Daniel took the apple' 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
    0.7::factA.
    0.05::factB.
    0.95::factC.
    
  
    %hop2
    conclusion:-xor(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Lily is a rhino' or 'Daniel took the apple' but not both.