context: It is highly unlikely that Mary moved to the garden. It is highly unlikely that Greg is a swan. Chances are about even that Julius is gray.
hypothesis: Chances are slight that either 'Mary moved to the garden' or 'Greg is a swan' but not both.
valid_hypothesis: Chances are slight that either 'Mary moved to the garden' or 'Greg is a swan' but not both.
invalid_hypothesis: It is highly likely that either 'Mary moved to the garden' or 'Greg is a swan' 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
    0.05::factA.
    0.05::factB.
    0.5::factC.
    
  
    %hop2
    conclusion:-xor(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Mary moved to the garden' or 'Greg is a swan' but not both.