It is impossible that Mary discarded the milk. Chances are about even that Lily is green. There is little chance that Daniel dropped the apple. There is almost no chance that if 'Lily is green and Daniel dropped the apple' then Brian is white. There is little chance that if either 'Lily is green' or 'Daniel dropped the apple' but not both then John got the football. It is probable that if 'Mary discarded the milk' or 'Daniel dropped the apple' or both then Bernhard is a rhino.
We believe that 'Bernhard is a rhino' or 'Daniel dropped the apple' or both.
Chances are slight that 'Bernhard is a rhino' or 'Daniel dropped the apple' or both.
We believe that 'Bernhard is a rhino' or 'Daniel dropped 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
  0.0::factA.
  0.5::factB.
  0.1::factC.
  %hop1
  0.02::factX:-and(factB,factC).
  0.1::factY:-xor(factB,factC).
  0.7::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Bernhard is a rhino' or 'Daniel dropped the apple' or both.