It is highly unlikely that Jessica is a cat. There is almost no chance that Brian is a swan. It is unlikely that Lily is a lion. It is certain that if either 'Lily is a lion' or 'Jessica is a cat' but not both then Greg is white. There is little chance that if either 'Brian is a swan' or 'Lily is a lion' but not both then John got the milk. Chances are slight that if 'Jessica is a cat and Lily is a lion' then Sumit is hungry.
It is probably not the case that 'Jessica is a cat' or 'Lily is a lion' or both.
It is probably not the case that 'Jessica is a cat' or 'Lily is a lion' or both.
It is almost certain that 'Jessica is a cat' or 'Lily is a lion' 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
  0.05::factA.
  0.02::factB.
  0.2::factC.
  %hop1
  1.0::factX:-xor(factC,factA).
  0.1::factY:-xor(factB,factC).
  0.1::factZ:-and(factA,factC).

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

  query(conclusion).
  
'Jessica is a cat' or 'Lily is a lion' or both.