It is highly likely that Lily is a swan. There is little chance that Sandra dropped the apple. It is highly likely that John went to the office. It is unlikely that if 'John went to the office and Lily is a swan' then Brian is white. It is almost certain that if 'Lily is a swan' or 'Sandra dropped the apple' or both then Jeff put down the milk. There is little chance that if either 'Sandra dropped the apple' or 'Lily is a swan' but not both then Bernhard is green.
It is likely that 'Lily is a swan and Sandra dropped the apple'.
It is improbable that 'Lily is a swan and Sandra dropped the apple'.
It is likely that 'Lily is a swan and Sandra dropped the apple'.

  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.
  0.1::factB.
  0.9::factC.
  %hop1
  0.2::factX:-and(factC,factA).
  0.95::factY:-or(factA,factB).
  0.1::factZ:-xor(factB,factA).

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

  query(conclusion).
  
'Lily is a swan and Sandra dropped the apple'.