It is almost certain that Mary picked up the apple. It is likely that Julius is a swan. We doubt that Greg is yellow. It is improbable that if either 'Julius is a swan' or 'Mary picked up the apple' but not both then Sumit is thirsty. It is impossible that if either 'Julius is a swan' or 'Mary picked up the apple' but not both then Bernhard is a frog. Chances are slight that if either 'Greg is yellow' or 'Julius is a swan' but not both then Sandra left the milk.
It is almost certain that 'Sandra left the milk' or 'Mary picked up the apple' or both.
It is almost certain that 'Sandra left the milk' or 'Mary picked up the apple' or both.
Chances are slight that 'Sandra left the milk' or 'Mary picked up the apple' 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
  0.95::factA.
  0.7::factB.
  0.2::factC.
  %hop1
  0.1::factX:-xor(factB,factA).
  0.0::factY:-xor(factB,factA).
  0.1::factZ:-xor(factC,factB).

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

  query(conclusion).
  
'Sandra left the milk' or 'Mary picked up the apple' or both.