Chances are slight that Mary went to the hallway. We doubt that Bernhard is green. There is a better than even chance that Brian is a lion. It is certain that if 'Bernhard is green' or 'Brian is a lion' or both then Julius is white. It is certain that if either 'Bernhard is green' or 'Brian is a lion' but not both then Gertrude is a cat. It is improbable that if either 'Bernhard is green' or 'Mary went to the hallway' but not both then Winona is a wolf.
It is improbable that 'Brian is a lion' or 'Winona is a wolf' or both.
There is a better than even chance that 'Brian is a lion' or 'Winona is a wolf' or both.
It is improbable that 'Brian is a lion' or 'Winona is a wolf' or 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.
  0.2::factB.
  0.6::factC.
  %hop1
  1.0::factX:-or(factB,factC).
  1.0::factY:-xor(factB,factC).
  0.1::factZ:-xor(factB,factA).

  %hop2
  conclusion:-or(factC,factZ).

  query(conclusion).
  
'Brian is a lion' or 'Winona is a wolf' or both.