We doubt that Antoine is thirsty. There is a very good chance that Lily is a swan. It is impossible that Greg is a rhino. It is probable that if 'Antoine is thirsty and Greg is a rhino' then Mary is in the bathroom. It is likely that if 'Lily is a swan' or 'Greg is a rhino' or both then Brian is yellow. It is impossible that if either 'Antoine is thirsty' or 'Greg is a rhino' but not both then Sandra dropped the milk.
It is impossible that 'Sandra dropped the milk and Lily is a swan'.
It is impossible that 'Sandra dropped the milk and Lily is a swan'.
Chances are about even that 'Sandra dropped the milk and Lily is a swan'.

  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
  0.2::factA.
  0.8::factB.
  0.0::factC.
  %hop1
  0.7::factX:-and(factA,factC).
  0.7::factY:-or(factB,factC).
  0.0::factZ:-xor(factA,factC).

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

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