It is improbable that Julius is green. We doubt that John dropped the apple. It is probably not the case that Bernhard is white. Chances are about even that if 'John dropped the apple and Julius is green' then Winona is a sheep. It is probable that if 'Bernhard is white' or 'John dropped the apple' or both then Greg is a rhino. We believe that if either 'Julius is green' or 'John dropped the apple' but not both then Brian is a frog.
There is a very good chance that 'Bernhard is white' or 'Julius is green' or both.
It is probably not the case that 'Bernhard is white' or 'Julius is green' or both.
There is a very good chance that 'Bernhard is white' or 'Julius is green' 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
  0.1::factA.
  0.2::factB.
  0.25::factC.
  %hop1
  0.5::factX:-and(factB,factA).
  0.7::factY:-or(factC,factB).
  0.75::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Bernhard is white' or 'Julius is green' or both.