There is almost no chance that Sandra left the apple. It is unlikely that Mary discarded the milk. It is almost certain that Lily is a rhino. It is almost certain that if 'Sandra left the apple' or 'Mary discarded the milk' or both then Bernhard is yellow. We doubt that if 'Lily is a rhino and Sandra left the apple' then Brian is white. There is almost no chance that if 'Sandra left the apple and Lily is a rhino' then John picked up the milk.
It is unlikely that 'Bernhard is yellow and Mary discarded the milk'.
It is unlikely that 'Bernhard is yellow and Mary discarded the milk'.
It is certain that 'Bernhard is yellow and Mary discarded the milk'.

  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
  0.02::factA.
  0.2::factB.
  0.95::factC.
  %hop1
  0.95::factX:-or(factA,factB).
  0.2::factY:-and(factC,factA).
  0.02::factZ:-and(factA,factC).

  %hop2
  conclusion:-and(factX,factB).

  query(conclusion).
  
'Bernhard is yellow and Mary discarded the milk'.