It is highly likely that Greg is a swan. There is almost no chance that Julius is a rhino. We doubt that Jessica is a cat. It is probable that if either 'Julius is a rhino' or 'Greg is a swan' but not both then Bernhard is yellow. It is probably the case that if either 'Jessica is a cat' or 'Greg is a swan' but not both then Sandra got the milk. It is impossible that if either 'Greg is a swan' or 'Julius is a rhino' but not both then John discarded the apple.
It is highly likely that either 'John discarded the apple' or 'Greg is a swan' but not both.
It is highly likely that either 'John discarded the apple' or 'Greg is a swan' but not both.
It is unlikely that either 'John discarded the apple' 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
  0.9::factA.
  0.02::factB.
  0.2::factC.
  %hop1
  0.7::factX:-xor(factB,factA).
  0.7::factY:-xor(factC,factA).
  0.0::factZ:-xor(factA,factB).

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

  query(conclusion).
  
Either 'John discarded the apple' or 'Greg is a swan' but not both.