We doubt that Sandra got the football. It is highly unlikely that Julius is a lion. Chances are about even that Bernhard is a swan. There is a very good chance that if either 'Sandra got the football' or 'Bernhard is a swan' but not both then Brian is white. It is almost certain that if 'Sandra got the football and Bernhard is a swan' then Jason is thirsty. There is a better than even chance that if 'Julius is a lion and Bernhard is a swan' then Lily is a lion.
It is highly likely that 'Brian is white and Sandra got the football'.
There is little chance that 'Brian is white and Sandra got the football'.
It is highly likely that 'Brian is white and Sandra got the football'.

  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
  0.2::factA.
  0.05::factB.
  0.5::factC.
  %hop1
  0.8::factX:-xor(factA,factC).
  0.95::factY:-and(factA,factC).
  0.6::factZ:-and(factB,factC).

  %hop2
  conclusion:-and(factX,factA).

  query(conclusion).
  
'Brian is white and Sandra got the football'.