It is probably the case that Sandra left the milk. There is little chance that Lily is a lion. It is likely that Mary grabbed the milk. There is little chance that if either 'Lily is a lion' or 'Sandra left the milk' but not both then Yann is thirsty. We believe that if either 'Lily is a lion' or 'Mary grabbed the milk' but not both then Greg is white. It is certain that if 'Sandra left the milk' or 'Mary grabbed the milk' or both then John went to the bedroom.
It is likely that 'Sandra left the milk and John went to the bedroom'.
It is likely that 'Sandra left the milk and John went to the bedroom'.
It is probably not the case that 'Sandra left the milk and John went to the bedroom'.

  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.
  0.1::factB.
  0.7::factC.
  %hop1
  0.1::factX:-xor(factB,factA).
  0.75::factY:-xor(factB,factC).
  1.0::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Sandra left the milk and John went to the bedroom'.