It is almost certain that Emily is a sheep. It is certain that Brian is green. There is almost no chance that Julius is a rhino. There is a better than even chance that if 'Emily is a sheep' or 'Brian is green' or both then Bernhard is a frog. It is almost certain that if either 'Emily is a sheep' or 'Julius is a rhino' but not both then Yann is bored. It is likely that if 'Julius is a rhino' or 'Emily is a sheep' or both then John went to the office.
Chances are about even that either 'Bernhard is a frog' or 'John went to the office' but not both.
Chances are about even that either 'Bernhard is a frog' or 'John went to the office' but not both.
It is highly unlikely that either 'Bernhard is a frog' or 'John went to the office' 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
  0.95::factA.
  1.0::factB.
  0.02::factC.
  %hop1
  0.6::factX:-or(factA,factB).
  0.95::factY:-xor(factA,factC).
  0.7::factZ:-or(factC,factA).

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

  query(conclusion).
  
Either 'Bernhard is a frog' or 'John went to the office' but not both.