It is certain that Mary left the football. Chances are slight that Daniel grabbed the milk. It is highly unlikely that Julius is white. It is impossible that if 'Daniel grabbed the milk and Mary left the football' then Lily is a swan. It is impossible that if either 'Mary left the football' or 'Julius is white' but not both then Winona is a wolf. We doubt that if 'Julius is white' or 'Mary left the football' or both then John got the apple.
Chances are slight that 'Daniel grabbed the milk and Mary left the football'.
Chances are slight that 'Daniel grabbed the milk and Mary left the football'.
We believe that 'Daniel grabbed the milk and Mary left 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
  1.0::factA.
  0.1::factB.
  0.05::factC.
  %hop1
  0.0::factX:-and(factB,factA).
  0.0::factY:-xor(factA,factC).
  0.2::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Daniel grabbed the milk and Mary left the football'.