It is improbable that Lily is a swan. It is probably not the case that Winona is a sheep. There is a better than even chance that Jeff left the apple. It is likely that if either 'Lily is a swan' or 'Jeff left the apple' but not both then Julius is white. It is probably the case that if 'Jeff left the apple and Winona is a sheep' then Mary went to the bedroom. It is impossible that if 'Lily is a swan' or 'Winona is a sheep' or both then Brian is yellow.
It is probably not the case that 'Lily is a swan' or 'Winona is a sheep' or both.
It is probably not the case that 'Lily is a swan' or 'Winona is a sheep' or both.
It is highly likely that 'Lily is a swan' or 'Winona is a sheep' 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.
  0.25::factB.
  0.6::factC.
  %hop1
  0.7::factX:-xor(factA,factC).
  0.7::factY:-and(factC,factB).
  0.0::factZ:-or(factA,factB).

  %hop2
  conclusion:-or(factA,factB).

  query(conclusion).
  
'Lily is a swan' or 'Winona is a sheep' or both.