context: There is a better than even chance that Julius is a swan. It is probable that Jessica is a mouse. Chances are slight that John got the apple. Chances are about even that if either 'Jessica is a mouse' or 'John got the apple' but not both then Winona is a wolf. There is a better than even chance that if either 'Jessica is a mouse' or 'John got the apple' but not both then Greg is a frog. It is impossible that if 'Julius is a swan' or 'Jessica is a mouse' or both then Mary moved to the garden.
hypothesis: There is almost no chance that either 'Jessica is a mouse' or 'Winona is a wolf' but not both.
valid_hypothesis: Chances are about even that either 'Jessica is a mouse' or 'Winona is a wolf' but not both.
invalid_hypothesis: There is almost no chance that either 'Jessica is a mouse' or 'Winona is a wolf' 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.
    0.7::factB.
    0.1::factC.
    %hop1
    0.5::factX:-xor(factB,factC).
    0.6::factY:-xor(factB,factC).
    0.0::factZ:-or(factA,factB).
  
    %hop2
    conclusion:-xor(factB,factX).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Jessica is a mouse' or 'Winona is a wolf' but not both.