It is probably the case that Jeff put down the milk. It is unlikely that Lily is a lion. There is little chance that Mary got the football. It is probably the case that if either 'Lily is a lion' or 'Jeff put down the milk' but not both then Bernhard is a swan. Chances are slight that if 'Lily is a lion' or 'Mary got the football' or both then Brian is yellow. We believe that if 'Lily is a lion' or 'Jeff put down the milk' or both then John went to the kitchen.
It is unlikely that 'Lily is a lion' or 'Jeff put down the milk' or both.
We believe that 'Lily is a lion' or 'Jeff put down the milk' or both.
It is unlikely that 'Lily is a lion' or 'Jeff put down 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.
  0.2::factB.
  0.1::factC.
  %hop1
  0.7::factX:-xor(factB,factA).
  0.1::factY:-or(factB,factC).
  0.75::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Lily is a lion' or 'Jeff put down the milk' or both.