It is unlikely that Jeff dropped the apple. It is likely that Julius is a lion. Chances are slight that Mary went to the bedroom. We believe that if either 'Jeff dropped the apple' or 'Julius is a lion' but not both then Fred is in the cinema. Chances are slight that if either 'Julius is a lion' or 'Jeff dropped the apple' but not both then Emily is a mouse. It is probable that if either 'Jeff dropped the apple' or 'Julius is a lion' but not both then Brian is green.
It is almost certain that either 'Julius is a lion' or 'Fred is in the cinema' but not both.
It is probably not the case that either 'Julius is a lion' or 'Fred is in the cinema' but not both.
It is almost certain that either 'Julius is a lion' or 'Fred is in the cinema' 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
  0.2::factA.
  0.7::factB.
  0.1::factC.
  %hop1
  0.75::factX:-xor(factA,factB).
  0.1::factY:-xor(factB,factA).
  0.7::factZ:-xor(factA,factB).

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

  query(conclusion).
  
Either 'Julius is a lion' or 'Fred is in the cinema' but not both.