Chances are slight that Mary went to the hallway. It is almost certain that Greg is a swan. We doubt that Daniel got the milk. It is impossible that if either 'Daniel got the milk' or 'Greg is a swan' but not both then Lily is a swan. It is likely that if 'Greg is a swan' or 'Daniel got the milk' or both then Julius is a rhino. It is improbable that if 'Daniel got the milk and Mary went to the hallway' then John grabbed the apple.
It is highly likely that either 'Julius is a rhino' or 'Greg is a swan' but not both.
It is probably not the case that either 'Julius is a rhino' or 'Greg is a swan' but not both.
It is highly likely that either 'Julius is a rhino' or 'Greg is a swan' 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.
  0.95::factB.
  0.2::factC.
  %hop1
  0.0::factX:-xor(factC,factB).
  0.7::factY:-or(factB,factC).
  0.1::factZ:-and(factC,factA).

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

  query(conclusion).
  
Either 'Julius is a rhino' or 'Greg is a swan' but not both.