Chances are slight that Julius is a rhino. There is a very good chance that Mary dropped the milk. It is probably not the case that Lily is a lion. There is little chance that if 'Mary dropped the milk and Lily is a lion' then Brian is gray. It is impossible that if either 'Lily is a lion' or 'Julius is a rhino' but not both then Daniel took the apple. It is probably not the case that if either 'Julius is a rhino' or 'Mary dropped the milk' but not both then John went to the kitchen.
There is a very good chance that either 'Daniel took the apple' or 'Lily is a lion' but not both.
It is probably not the case that either 'Daniel took the apple' or 'Lily is a lion' but not both.
There is a very good chance that either 'Daniel took the apple' or 'Lily 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
  0.1::factA.
  0.8::factB.
  0.25::factC.
  %hop1
  0.1::factX:-and(factB,factC).
  0.0::factY:-xor(factC,factA).
  0.25::factZ:-xor(factA,factB).

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

  query(conclusion).
  
Either 'Daniel took the apple' or 'Lily is a lion' but not both.