It is probable that Sandra got the milk. It is probably not the case that Mary went to the hallway. There is little chance that Brian is a lion. It is almost certain that if 'Brian is a lion and Mary went to the hallway' then Bernhard is green. There is a very good chance that if 'Mary went to the hallway and Brian is a lion' then Greg is a rhino. It is unlikely that if 'Sandra got the milk and Brian is a lion' then Winona is a wolf.
There is little chance that either 'Bernhard is green' or 'Brian is a lion' but not both.
There is little chance that either 'Bernhard is green' or 'Brian is a lion' but not both.
There is a better than even chance that either 'Bernhard is green' or 'Brian 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.
  0.25::factB.
  0.1::factC.
  %hop1
  0.95::factX:-and(factC,factB).
  0.8::factY:-and(factB,factC).
  0.2::factZ:-and(factA,factC).

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

  query(conclusion).
  
Either 'Bernhard is green' or 'Brian is a lion' but not both.