It is highly likely that Bernhard is yellow. It is probably the case that Daniel grabbed the apple. It is improbable that John went to the bedroom. There is a very good chance that if either 'Daniel grabbed the apple' or 'Bernhard is yellow' but not both then Sandra left the milk. It is highly unlikely that if 'Daniel grabbed the apple and John went to the bedroom' then Julius is a lion. There is a very good chance that if 'Bernhard is yellow' or 'John went to the bedroom' or both then Mary dropped the milk.
It is probably not the case that either 'Sandra left the milk' or 'Julius is a lion' but not both.
It is probably not the case that either 'Sandra left the milk' or 'Julius is a lion' but not both.
It is likely that either 'Sandra left the milk' or 'Julius 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
  0.9::factA.
  0.7::factB.
  0.1::factC.
  %hop1
  0.8::factX:-xor(factB,factA).
  0.05::factY:-and(factB,factC).
  0.8::factZ:-or(factA,factC).

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

  query(conclusion).
  
Either 'Sandra left the milk' or 'Julius is a lion' but not both.