There is a better than even chance that Lily is a swan. There is a very good chance that Jeff put down the milk. It is probably not the case that Brian is white. There is a better than even chance that if either 'Lily is a swan' or 'Jeff put down the milk' but not both then Mary went to the hallway. There is a very good chance that if 'Lily is a swan and Jeff put down the milk' then Greg is a rhino. It is probable that if 'Jeff put down the milk' or 'Brian is white' or both then John took the apple.
It is unlikely that 'Mary went to the hallway and Jeff put down the milk'.
It is unlikely that 'Mary went to the hallway and Jeff put down the milk'.
It is probably the case that 'Mary went to the hallway and Jeff put down 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
  0.6::factA.
  0.8::factB.
  0.25::factC.
  %hop1
  0.6::factX:-xor(factA,factB).
  0.8::factY:-and(factA,factB).
  0.7::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Mary went to the hallway and Jeff put down the milk'.