context: It is probably not the case that Greg is green. It is improbable that Winona is a wolf. It is probably the case that Brian is white. It is highly likely that if 'Winona is a wolf and Greg is green' then Gertrude is a sheep. It is almost certain that if 'Winona is a wolf' or 'Greg is green' or both then Lily is a lion. It is highly likely that if 'Greg is green and Winona is a wolf' then Mary grabbed the apple.
hypothesis: It is highly likely that either 'Gertrude is a sheep' or 'Lily is a lion' but not both.
valid_hypothesis: It is probably not the case that either 'Gertrude is a sheep' or 'Lily is a lion' but not both.
invalid_hypothesis: It is highly likely that either 'Gertrude is a sheep' or 'Lily is a lion' 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.
    0.1::factB.
    0.7::factC.
    %hop1
    0.9::factX:-and(factB,factA).
    0.95::factY:-or(factB,factA).
    0.9::factZ:-and(factA,factB).
  
    %hop2
    conclusion:-xor(factX,factY).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Gertrude is a sheep' or 'Lily is a lion' but not both.