Chances are about even that Julius is a lion. It is probably the case that Sumit is tired. It is unlikely that Brian is white. It is unlikely that if either 'Julius is a lion' or 'Sumit is tired' but not both then Greg is green. Chances are about even that if either 'Brian is white' or 'Julius is a lion' but not both then Sandra dropped the milk. There is almost no chance that if 'Julius is a lion' or 'Sumit is tired' or both then John went to the office.
It is almost certain that either 'John went to the office' or 'Sandra dropped the milk' but not both.
It is probably not the case that either 'John went to the office' or 'Sandra dropped the milk' but not both.
It is almost certain that either 'John went to the office' or 'Sandra dropped 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
  0.5::factA.
  0.7::factB.
  0.2::factC.
  %hop1
  0.2::factX:-xor(factA,factB).
  0.5::factY:-xor(factC,factA).
  0.02::factZ:-or(factA,factB).

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

  query(conclusion).
  
Either 'John went to the office' or 'Sandra dropped the milk' but not both.