It is impossible that Lily is yellow. It is almost certain that Jason is tired. There is almost no chance that Mary went to the office. It is likely that if 'Mary went to the office' or 'Lily is yellow' or both then Greg is green. Chances are about even that if 'Jason is tired' or 'Mary went to the office' or both then John left the milk. It is certain that if either 'Lily is yellow' or 'Jason is tired' but not both then Julius is white.
Chances are about even that either 'Julius is white' or 'John left the milk' but not both.
Chances are about even that either 'Julius is white' or 'John left the milk' but not both.
There is almost no chance that either 'Julius is white' or 'John left the milk' but not 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.
  0.95::factB.
  0.02::factC.
  %hop1
  0.7::factX:-or(factC,factA).
  0.5::factY:-or(factB,factC).
  1.0::factZ:-xor(factA,factB).

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

  query(conclusion).
  
Either 'Julius is white' or 'John left the milk' but not both.