It is likely that Mary took the football. It is highly unlikely that John left the milk. There is a better than even chance that Jeff dropped the apple. It is impossible that if 'Jeff dropped the apple and John left the milk' then Emily is a sheep. It is improbable that if 'Jeff dropped the apple' or 'Mary took the football' or both then Bernhard is gray. It is highly likely that if 'Jeff dropped the apple and Mary took the football' then Lily is yellow.
There is little chance that 'Bernhard is gray' or 'John left the milk' or both.
There is little chance that 'Bernhard is gray' or 'John left the milk' or both.
There is a better than even chance that 'Bernhard is gray' or 'John 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
  0.7::factA.
  0.05::factB.
  0.6::factC.
  %hop1
  0.0::factX:-and(factC,factB).
  0.1::factY:-or(factC,factA).
  0.9::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Bernhard is gray' or 'John left the milk' or both.