There is a very good chance that Daniel grabbed the milk. We believe that Julius is a rhino. There is a very good chance that Lily is a lion. There is a very good chance that if 'Lily is a lion' or 'Daniel grabbed the milk' or both then Brian is white. Chances are about even that if 'Julius is a rhino' or 'Daniel grabbed the milk' or both then John took the apple. It is impossible that if 'Daniel grabbed the milk' or 'Julius is a rhino' or both then Mary went to the office.
It is almost certain that 'Julius is a rhino' or 'Brian is white' or both.
It is almost certain that 'Julius is a rhino' or 'Brian is white' or both.
Chances are about even that 'Julius is a rhino' or 'Brian is white' 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
  0.8::factA.
  0.75::factB.
  0.8::factC.
  %hop1
  0.8::factX:-or(factC,factA).
  0.5::factY:-or(factB,factA).
  0.0::factZ:-or(factA,factB).

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

  query(conclusion).
  
'Julius is a rhino' or 'Brian is white' or both.