It is highly unlikely that Julius is white. We believe that Mary went to the kitchen. It is almost certain that Lily is a rhino. We believe that if either 'Julius is white' or 'Lily is a rhino' but not both then Bernhard is gray. It is unlikely that if 'Lily is a rhino' or 'Julius is white' or both then Bill moved to the office. It is probably the case that if either 'Lily is a rhino' or 'Julius is white' but not both then John put down the milk.
We believe that either 'Lily is a rhino' or 'Bill moved to the office' but not both.
We believe that either 'Lily is a rhino' or 'Bill moved to the office' but not both.
It is probably not the case that either 'Lily is a rhino' or 'Bill moved 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
  0.05::factA.
  0.75::factB.
  0.95::factC.
  %hop1
  0.75::factX:-xor(factA,factC).
  0.2::factY:-or(factC,factA).
  0.7::factZ:-xor(factC,factA).

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

  query(conclusion).
  
Either 'Lily is a rhino' or 'Bill moved to the office' but not both.