It is highly unlikely that Julius is gray. Chances are slight that Sandra left the football. It is probably not the case that Lily is a lion. There is a very good chance that if either 'Julius is gray' or 'Lily is a lion' but not both then Bernhard is a rhino. It is highly unlikely that if 'Julius is gray' or 'Sandra left the football' or both then John discarded the apple. Chances are slight that if 'Lily is a lion' or 'Sandra left the football' or both then Mary went to the kitchen.
There is almost no chance that 'Lily is a lion and Julius is gray'.
There is almost no chance that 'Lily is a lion and Julius is gray'.
Chances are about even that 'Lily is a lion and Julius is gray'.

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

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

  query(conclusion).
  
'Lily is a lion and Julius is gray'.