It is unlikely that Lily is white. It is likely that Brian is a rhino. It is probably not the case that Mary went to the bedroom. It is likely that if 'Mary went to the bedroom and Brian is a rhino' then Julius is gray. It is certain that if either 'Mary went to the bedroom' or 'Brian is a rhino' but not both then Sandra left the milk. It is highly likely that if 'Mary went to the bedroom' or 'Brian is a rhino' or both then John got the milk.
It is impossible that either 'Julius is gray' or 'Brian is a rhino' but not both.
There is a better than even chance that either 'Julius is gray' or 'Brian is a rhino' but not both.
It is impossible that either 'Julius is gray' or 'Brian is a rhino' 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
  0.2::factA.
  0.7::factB.
  0.25::factC.
  %hop1
  0.7::factX:-and(factC,factB).
  1.0::factY:-xor(factC,factB).
  0.9::factZ:-or(factC,factB).

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

  query(conclusion).
  
Either 'Julius is gray' or 'Brian is a rhino' but not both.