It is probably not the case that Mary took the milk. There is little chance that Daniel left the milk. It is certain that Bernhard is yellow. We believe that if 'Mary took the milk' or 'Bernhard is yellow' or both then Julius is gray. Chances are about even that if 'Bernhard is yellow and Daniel left the milk' then Greg is a rhino. It is highly likely that if 'Bernhard is yellow' or 'Mary took the milk' or both then Lily is white.
Chances are slight that 'Bernhard is yellow' or 'Lily is white' or both.
It is certain that 'Bernhard is yellow' or 'Lily is white' or both.
Chances are slight that 'Bernhard is yellow' or 'Lily is white' 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
  0.25::factA.
  0.1::factB.
  1.0::factC.
  %hop1
  0.75::factX:-or(factA,factC).
  0.5::factY:-and(factC,factB).
  0.9::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Bernhard is yellow' or 'Lily is white' or both.