There is little chance that Julius is a swan. It is unlikely that Lily is a rhino. It is probably not the case that Winona is a sheep. There is little chance that if 'Lily is a rhino' or 'Julius is a swan' or both then John got the apple. It is almost certain that if 'Lily is a rhino and Julius is a swan' then Mary left the milk. There is a better than even chance that if either 'Lily is a rhino' or 'Julius is a swan' but not both then Greg is yellow.
There is a very good chance that either 'Lily is a rhino' or 'John got the apple' but not both.
It is unlikely that either 'Lily is a rhino' or 'John got the apple' but not both.
There is a very good chance that either 'Lily is a rhino' or 'John got the apple' 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
  0.1::factA.
  0.2::factB.
  0.25::factC.
  %hop1
  0.1::factX:-or(factB,factA).
  0.95::factY:-and(factB,factA).
  0.6::factZ:-xor(factB,factA).

  %hop2
  conclusion:-xor(factB,factX).

  query(conclusion).
  
Either 'Lily is a rhino' or 'John got the apple' but not both.