Chances are about even that Julius is yellow. It is almost certain that John put down the apple. There is a very good chance that Brian is a rhino. It is almost certain that if either 'Brian is a rhino' or 'Julius is yellow' but not both then Mary moved to the garden. It is highly likely that if 'Julius is yellow' or 'John put down the apple' or both then Fred dropped the milk. It is highly unlikely that if 'John put down the apple' or 'Julius is yellow' or both then Antoine is thirsty.
Chances are about even that either 'Julius is yellow' or 'John put down the apple' but not both.
Chances are about even that either 'Julius is yellow' or 'John put down the apple' but not both.
It is highly unlikely that either 'Julius is yellow' or 'John put down the apple' 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
  0.5::factA.
  0.95::factB.
  0.8::factC.
  %hop1
  0.95::factX:-xor(factC,factA).
  0.9::factY:-or(factA,factB).
  0.05::factZ:-or(factB,factA).

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

  query(conclusion).
  
Either 'Julius is yellow' or 'John put down the apple' but not both.