It is probably the case that Julius is white. It is probably not the case that Bernhard is a swan. It is highly unlikely that Daniel got the milk. It is highly likely that if 'Daniel got the milk and Bernhard is a swan' then Greg is gray. It is almost certain that if either 'Daniel got the milk' or 'Julius is white' but not both then Jessica is a mouse. It is highly unlikely that if 'Bernhard is a swan' or 'Julius is white' or both then Mary went to the kitchen.
It is impossible that 'Daniel got the milk' or 'Jessica is a mouse' or both.
It is likely that 'Daniel got the milk' or 'Jessica is a mouse' or both.
It is impossible that 'Daniel got the milk' or 'Jessica is a mouse' 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
  0.7::factA.
  0.25::factB.
  0.05::factC.
  %hop1
  0.9::factX:-and(factC,factB).
  0.95::factY:-xor(factC,factA).
  0.05::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Daniel got the milk' or 'Jessica is a mouse' or both.