It is highly likely that Emily is a sheep. It is certain that Julius is white. It is probably not the case that Mary left the milk. It is probably not the case that if 'Mary left the milk and Julius is white' then Bernhard is green. We believe that if either 'Mary left the milk' or 'Julius is white' but not both then John discarded the apple. It is probable that if 'Mary left the milk and Emily is a sheep' then Lily is a lion.
There is little chance that 'John discarded the apple' or 'Bernhard is green' or both.
There is a better than even chance that 'John discarded the apple' or 'Bernhard is green' or both.
There is little chance that 'John discarded the apple' or 'Bernhard is green' 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
  0.9::factA.
  1.0::factB.
  0.25::factC.
  %hop1
  0.25::factX:-and(factC,factB).
  0.75::factY:-xor(factC,factB).
  0.7::factZ:-and(factC,factA).

  %hop2
  conclusion:-or(factY,factX).

  query(conclusion).
  
'John discarded the apple' or 'Bernhard is green' or both.