It is probably the case that Jason is tired. It is almost certain that John went to the kitchen. We doubt that Brian is a lion. There is a better than even chance that if 'Jason is tired' or 'John went to the kitchen' or both then Julius is a rhino. Chances are about even that if 'Brian is a lion and Jason is tired' then Lily is a frog. It is certain that if either 'Jason is tired' or 'Brian is a lion' but not both then Mary got the apple.
There is a better than even chance that either 'Julius is a rhino' or 'Brian is a lion' but not both.
There is a better than even chance that either 'Julius is a rhino' or 'Brian is a lion' but not both.
It is impossible that either 'Julius is a rhino' or 'Brian is a lion' 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
  0.7::factA.
  0.95::factB.
  0.2::factC.
  %hop1
  0.6::factX:-or(factA,factB).
  0.5::factY:-and(factC,factA).
  1.0::factZ:-xor(factA,factC).

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

  query(conclusion).
  
Either 'Julius is a rhino' or 'Brian is a lion' but not both.