There is a very good chance that Brian is white. It is impossible that Daniel took the apple. Chances are about even that Greg is a swan. It is unlikely that if 'Greg is a swan' or 'Daniel took the apple' or both then Julius is yellow. There is almost no chance that if 'Brian is white' or 'Greg is a swan' or both then John moved to the office. It is probably the case that if either 'Brian is white' or 'Greg is a swan' but not both then Bernhard is a rhino.
It is improbable that 'John moved to the office' or 'Julius is yellow' or both.
It is improbable that 'John moved to the office' or 'Julius is yellow' or both.
It is almost certain that 'John moved to the office' or 'Julius is yellow' 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.
  0.0::factB.
  0.5::factC.
  %hop1
  0.2::factX:-or(factC,factB).
  0.02::factY:-or(factA,factC).
  0.7::factZ:-xor(factA,factC).

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

  query(conclusion).
  
'John moved to the office' or 'Julius is yellow' or both.