context: It is probably not the case that John went to the kitchen. We doubt that Jeff left the apple. It is highly likely that Lily is a rhino.
hypothesis: It is impossible that either 'John went to the kitchen' or 'Lily is a rhino' but not both.
valid_hypothesis: It is probably the case that either 'John went to the kitchen' or 'Lily is a rhino' but not both.
invalid_hypothesis: It is impossible that either 'John went to the kitchen' or 'Lily 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
    0.25::factA.
    0.2::factB.
    0.9::factC.
    
  
    %hop2
    conclusion:-xor(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: Either 'John went to the kitchen' or 'Lily is a rhino' but not both.