There is little chance that Brian is yellow. It is almost certain that Lily is a lion. We doubt that Julius is a swan. We believe that if either 'Lily is a lion' or 'Julius is a swan' but not both then Bernhard is gray. It is improbable that if 'Lily is a lion and Brian is yellow' then Bill left the milk. There is a very good chance that if either 'Julius is a swan' or 'Lily is a lion' but not both then John dropped the apple.
There is a very good chance that 'Lily is a lion and Brian is yellow'.
Chances are slight that 'Lily is a lion and Brian is yellow'.
There is a very good chance that 'Lily is a lion and Brian is yellow'.

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

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

  query(conclusion).
  
'Lily is a lion and Brian is yellow'.