There is a very good chance that Mary dropped the milk. There is a very good chance that Daniel got the milk. We doubt that Greg is a swan. It is likely that if 'Greg is a swan and Mary dropped the milk' then Lily is green. It is unlikely that if 'Daniel got the milk and Mary dropped the milk' then Brian is a lion. It is almost certain that if 'Daniel got the milk' or 'Greg is a swan' or both then Julius is green.
It is probably the case that either 'Julius is green' or 'Brian is a lion' but not both.
It is probably the case that either 'Julius is green' or 'Brian is a lion' but not both.
There is almost no chance that either 'Julius is green' 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
  0.8::factA.
  0.8::factB.
  0.2::factC.
  %hop1
  0.7::factX:-and(factC,factA).
  0.2::factY:-and(factB,factA).
  0.95::factZ:-or(factB,factC).

  %hop2
  conclusion:-xor(factZ,factY).

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