It is impossible that Julius is green. Chances are about even that Lily is a rhino. There is a better than even chance that Bernhard is gray. We doubt that if either 'Lily is a rhino' or 'Bernhard is gray' but not both then Daniel dropped the apple. There is a very good chance that if either 'Bernhard is gray' or 'Lily is a rhino' but not both then Mary went to the office. There is a better than even chance that if 'Julius is green and Lily is a rhino' then Brian is a frog.
There is a better than even chance that either 'Daniel dropped the apple' or 'Bernhard is gray' but not both.
There is a better than even chance that either 'Daniel dropped the apple' or 'Bernhard is gray' but not both.
It is improbable that either 'Daniel dropped the apple' or 'Bernhard is gray' 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
  0.0::factA.
  0.5::factB.
  0.6::factC.
  %hop1
  0.2::factX:-xor(factB,factC).
  0.8::factY:-xor(factC,factB).
  0.6::factZ:-and(factA,factB).

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

  query(conclusion).
  
Either 'Daniel dropped the apple' or 'Bernhard is gray' but not both.