It is almost certain that Greg is a rhino. It is highly likely that Lily is a swan. There is a better than even chance that John left the milk. It is probably not the case that if 'Greg is a rhino and Lily is a swan' then Bernhard is green. There is almost no chance that if 'Lily is a swan' or 'John left the milk' or both then Gertrude is a sheep. There is a very good chance that if either 'John left the milk' or 'Greg is a rhino' but not both then Julius is a frog.
There is almost no chance that 'Greg is a rhino' or 'Lily is a swan' or both.
It is certain that 'Greg is a rhino' or 'Lily is a swan' or both.
There is almost no chance that 'Greg is a rhino' or 'Lily is a swan' or 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.
  0.9::factB.
  0.6::factC.
  %hop1
  0.25::factX:-and(factA,factB).
  0.02::factY:-or(factB,factC).
  0.8::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'Greg is a rhino' or 'Lily is a swan' or both.