It is probably the case that Lily is a rhino. Chances are slight that Daniel left the milk. It is certain that Bernhard is a lion. There is a better than even chance that if 'Lily is a rhino and Daniel left the milk' then Mary moved to the office. It is improbable that if 'Daniel left the milk' or 'Bernhard is a lion' or both then Sandra took the apple. There is almost no chance that if 'Daniel left the milk' or 'Lily is a rhino' or both then Brian is a rhino.
It is almost certain that either 'Mary moved to the office' or 'Bernhard is a lion' but not both.
It is almost certain that either 'Mary moved to the office' or 'Bernhard is a lion' but not both.
Chances are slight that either 'Mary moved to the office' 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
  0.7::factA.
  0.1::factB.
  1.0::factC.
  %hop1
  0.6::factX:-and(factA,factB).
  0.1::factY:-or(factB,factC).
  0.02::factZ:-or(factB,factA).

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

  query(conclusion).
  
Either 'Mary moved to the office' or 'Bernhard is a lion' but not both.