Chances are about even that Bill got the milk there. It is certain that Greg is a lion. There is almost no chance that Bernhard is green. There is almost no chance that if either 'Bill got the milk there' or 'Greg is a lion' but not both then Fred left the apple. There is a better than even chance that if either 'Greg is a lion' or 'Bernhard is green' but not both then Jeff went to the garden. There is a better than even chance that if 'Bernhard is green' or 'Bill got the milk there' or both then Julius is white.
It is impossible that 'Julius is white' or 'Jeff went to the garden' or both.
It is likely that 'Julius is white' or 'Jeff went to the garden' or both.
It is impossible that 'Julius is white' or 'Jeff went to the garden' 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
  0.5::factA.
  1.0::factB.
  0.02::factC.
  %hop1
  0.02::factX:-xor(factA,factB).
  0.6::factY:-xor(factB,factC).
  0.6::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Julius is white' or 'Jeff went to the garden' or both.