It is highly unlikely that Mary went to the garden. We believe that Bernhard is a lion. There is a very good chance that Julius is a rhino. It is probable that if either 'Mary went to the garden' or 'Julius is a rhino' but not both then Daniel put down the milk. It is highly unlikely that if either 'Julius is a rhino' or 'Mary went to the garden' but not both then Jessica is a sheep. Chances are slight that if either 'Julius is a rhino' or 'Bernhard is a lion' but not both then Brian is a swan.
It is probably not the case that either 'Julius is a rhino' or 'Bernhard is a lion' but not both.
It is probably not the case that either 'Julius is a rhino' or 'Bernhard is a lion' but not both.
It is almost certain that either 'Julius is a rhino' or 'Bernhard is a lion' 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
  0.05::factA.
  0.75::factB.
  0.8::factC.
  %hop1
  0.7::factX:-xor(factA,factC).
  0.05::factY:-xor(factC,factA).
  0.1::factZ:-xor(factC,factB).

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

  query(conclusion).
  
Either 'Julius is a rhino' or 'Bernhard is a lion' but not both.