It is probably not the case that Brian is white. It is improbable that Daniel got the milk. Chances are slight that Lily is yellow. It is unlikely that if either 'Brian is white' or 'Lily is yellow' but not both then Sandra dropped the milk. There is a very good chance that if 'Daniel got the milk and Lily is yellow' then Julius is a lion. We doubt that if 'Brian is white' or 'Daniel got the milk' or both then Sumit is thirsty.
It is impossible that 'Julius is a lion and Sumit is thirsty'.
It is impossible that 'Julius is a lion and Sumit is thirsty'.
Chances are about even that 'Julius is a lion and Sumit is thirsty'.

  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
  0.25::factA.
  0.1::factB.
  0.1::factC.
  %hop1
  0.2::factX:-xor(factA,factC).
  0.8::factY:-and(factB,factC).
  0.2::factZ:-or(factA,factB).

  %hop2
  conclusion:-and(factY,factZ).

  query(conclusion).
  
'Julius is a lion and Sumit is thirsty'.