It is probable that Julius is a frog. We doubt that Lily is a swan. There is a better than even chance that Daniel got the football. It is unlikely that if 'Lily is a swan and Daniel got the football' then Sumit is thirsty. We believe that if either 'Daniel got the football' or 'Julius is a frog' but not both then Mary dropped the milk. There is a better than even chance that if 'Daniel got the football' or 'Julius is a frog' or both then John moved to the office.
It is probably not the case that either 'Mary dropped the milk' or 'Sumit is thirsty' but not both.
It is probably not the case that either 'Mary dropped the milk' or 'Sumit is thirsty' but not both.
It is likely that either 'Mary dropped the milk' or 'Sumit is thirsty' 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
  0.7::factA.
  0.2::factB.
  0.6::factC.
  %hop1
  0.2::factX:-and(factB,factC).
  0.75::factY:-xor(factC,factA).
  0.6::factZ:-or(factC,factA).

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

  query(conclusion).
  
Either 'Mary dropped the milk' or 'Sumit is thirsty' but not both.