It is highly likely that Mary moved to the garden. There is almost no chance that Brian is a lion. It is improbable that Emily is a mouse. It is highly unlikely that if either 'Brian is a lion' or 'Mary moved to the garden' but not both then Julius is white. It is almost certain that if 'Emily is a mouse' or 'Mary moved to the garden' or both then Lily is a swan. It is impossible that if either 'Brian is a lion' or 'Emily is a mouse' but not both then John dropped the milk.
It is improbable that either 'Lily is a swan' or 'John dropped the milk' but not both.
It is highly likely that either 'Lily is a swan' or 'John dropped the milk' but not both.
It is improbable that either 'Lily is a swan' or 'John dropped the milk' 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
  0.9::factA.
  0.02::factB.
  0.1::factC.
  %hop1
  0.05::factX:-xor(factB,factA).
  0.95::factY:-or(factC,factA).
  0.0::factZ:-xor(factB,factC).

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

  query(conclusion).
  
Either 'Lily is a swan' or 'John dropped the milk' but not both.