There is a very good chance that Greg is gray. It is almost certain that Winona is a cat. It is highly unlikely that Lily is a lion. It is highly unlikely that if either 'Greg is gray' or 'Lily is a lion' but not both then Daniel grabbed the milk. Chances are about even that if 'Winona is a cat and Lily is a lion' then Brian is white. There is almost no chance that if 'Winona is a cat' or 'Greg is gray' or both then John went to the bedroom.
It is almost certain that either 'Lily is a lion' or 'John went to the bedroom' but not both.
It is highly unlikely that either 'Lily is a lion' or 'John went to the bedroom' but not both.
It is almost certain that either 'Lily is a lion' or 'John went to the bedroom' but not both.

  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
  0.8::factA.
  0.95::factB.
  0.05::factC.
  %hop1
  0.05::factX:-xor(factA,factC).
  0.5::factY:-and(factB,factC).
  0.02::factZ:-or(factB,factA).

  %hop2
  conclusion:-xor(factC,factZ).

  query(conclusion).
  
Either 'Lily is a lion' or 'John went to the bedroom' but not both.