It is certain that Lily is a swan. It is probably not the case that Julius is a lion. It is highly unlikely that Brian is white. It is unlikely that if either 'Lily is a swan' or 'Julius is a lion' but not both then Jessica is a mouse. There is a very good chance that if either 'Brian is white' or 'Julius is a lion' but not both then Greg is a rhino. It is highly unlikely that if 'Brian is white and Lily is a swan' then John left the apple.
It is almost certain that 'Brian is white' or 'Jessica is a mouse' or both.
We doubt that 'Brian is white' or 'Jessica is a mouse' or both.
It is almost certain that 'Brian is white' or 'Jessica is a mouse' 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
  1.0::factA.
  0.25::factB.
  0.05::factC.
  %hop1
  0.2::factX:-xor(factA,factB).
  0.8::factY:-xor(factC,factB).
  0.05::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Brian is white' or 'Jessica is a mouse' or both.