It is highly unlikely that Bernhard is a swan. There is a better than even chance that Daniel grabbed the milk. We doubt that Sumit is thirsty. There is a very good chance that if 'Bernhard is a swan and Daniel grabbed the milk' then Mary moved to the garden. It is improbable that if 'Daniel grabbed the milk and Bernhard is a swan' then Brian is green. It is improbable that if 'Bernhard is a swan and Sumit is thirsty' then Julius is a rhino.
There is a better than even chance that 'Daniel grabbed the milk' or 'Bernhard is a swan' or both.
There is a better than even chance that 'Daniel grabbed the milk' or 'Bernhard is a swan' or both.
It is impossible that 'Daniel grabbed the milk' or 'Bernhard is a swan' 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
  0.05::factA.
  0.6::factB.
  0.2::factC.
  %hop1
  0.8::factX:-and(factA,factB).
  0.1::factY:-and(factB,factA).
  0.1::factZ:-and(factA,factC).

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

  query(conclusion).
  
'Daniel grabbed the milk' or 'Bernhard is a swan' or both.