It is almost certain that Jeff left the apple. It is highly unlikely that Julius is a rhino. It is probable that Fred discarded the apple. It is highly unlikely that if 'Fred discarded the apple' or 'Jeff left the apple' or both then Jessica is a mouse. It is probably not the case that if either 'Julius is a rhino' or 'Jeff left the apple' but not both then Bernhard is a swan. It is probably the case that if 'Jeff left the apple and Fred discarded the apple' then Sandra got the football.
It is impossible that either 'Jeff left the apple' or 'Jessica is a mouse' but not both.
It is highly likely that either 'Jeff left the apple' or 'Jessica is a mouse' but not both.
It is impossible that either 'Jeff left the apple' 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
  0.95::factA.
  0.05::factB.
  0.7::factC.
  %hop1
  0.05::factX:-or(factC,factA).
  0.25::factY:-xor(factB,factA).
  0.7::factZ:-and(factA,factC).

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

  query(conclusion).
  
Either 'Jeff left the apple' or 'Jessica is a mouse' but not both.