It is impossible that Julius is a swan. It is probably the case that Bernhard is green. We believe that Greg is a swan. There is almost no chance that if either 'Greg is a swan' or 'Julius is a swan' but not both then John moved to the garden. It is highly unlikely that if 'Greg is a swan' or 'Julius is a swan' or both then Sandra got the football. There is almost no chance that if either 'Julius is a swan' or 'Bernhard is green' but not both then Mary went to the office.
There is a very good chance that 'John moved to the garden' or 'Julius is a swan' or both.
There is almost no chance that 'John moved to the garden' or 'Julius is a swan' or both.
There is a very good chance that 'John moved to the garden' or 'Julius 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
  0.0::factA.
  0.7::factB.
  0.75::factC.
  %hop1
  0.02::factX:-xor(factC,factA).
  0.05::factY:-or(factC,factA).
  0.02::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'John moved to the garden' or 'Julius is a swan' or both.