It is certain that Jeff left the apple. Chances are about even that Jessica is a mouse. There is a very good chance that Julius is white. It is highly likely that if 'Julius is white and Jeff left the apple' then Lily is a swan. It is probably not the case that if either 'Jessica is a mouse' or 'Jeff left the apple' but not both then Mary went to the hallway. Chances are about even that if 'Jeff left the apple and Jessica is a mouse' then Greg is a frog.
Chances are about even that either 'Lily is a swan' or 'Jessica is a mouse' but not both.
Chances are about even that either 'Lily is a swan' or 'Jessica is a mouse' but not both.
It is certain that either 'Lily is a swan' or 'Jessica is a mouse' but not 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.
  0.5::factB.
  0.8::factC.
  %hop1
  0.9::factX:-and(factC,factA).
  0.25::factY:-xor(factB,factA).
  0.5::factZ:-and(factA,factB).

  %hop2
  conclusion:-xor(factX,factB).

  query(conclusion).
  
Either 'Lily is a swan' or 'Jessica is a mouse' but not both.