There is almost no chance that Julius is yellow. There is almost no chance that Lily is a swan. It is probably the case that Daniel dropped the milk. Chances are about even that if 'Lily is a swan and Julius is yellow' then John picked up the apple. It is impossible that if 'Daniel dropped the milk and Lily is a swan' then Bill went to the kitchen. It is probably the case that if 'Julius is yellow and Lily is a swan' then Sandra left the football.
There is almost no chance that 'Lily is a swan' or 'Sandra left the football' or both.
There is almost no chance that 'Lily is a swan' or 'Sandra left the football' or both.
It is likely that 'Lily is a swan' or 'Sandra left the football' 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
  0.02::factA.
  0.02::factB.
  0.7::factC.
  %hop1
  0.5::factX:-and(factB,factA).
  0.0::factY:-and(factC,factB).
  0.7::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Lily is a swan' or 'Sandra left the football' or both.