There is a better than even chance that Daniel left the milk. It is highly likely that Sandra dropped the milk. It is certain that Greg is yellow. It is probably the case that if 'Daniel left the milk' or 'Sandra dropped the milk' or both then Winona is a mouse. It is improbable that if either 'Daniel left the milk' or 'Greg is yellow' but not both then John went to the hallway. Chances are about even that if 'Sandra dropped the milk' or 'Greg is yellow' or both then Lily is a frog.
It is almost certain that 'Sandra dropped the milk' or 'Daniel left the milk' or both.
It is almost certain that 'Sandra dropped the milk' or 'Daniel left the milk' or both.
Chances are slight that 'Sandra dropped the milk' or 'Daniel left the milk' 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
  0.6::factA.
  0.9::factB.
  1.0::factC.
  %hop1
  0.7::factX:-or(factA,factB).
  0.1::factY:-xor(factA,factC).
  0.5::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Sandra dropped the milk' or 'Daniel left the milk' or both.