There is a better than even chance that Lily is white. It is highly likely that Bernhard is a frog. It is highly likely that Sandra left the milk. It is improbable that if either 'Bernhard is a frog' or 'Lily is white' but not both then Julius is a rhino. It is probably not the case that if 'Sandra left the milk and Bernhard is a frog' then Brian is gray. It is impossible that if 'Lily is white' or 'Bernhard is a frog' or both then Antoine is hungry.
There is a very good chance that 'Bernhard is a frog and Julius is a rhino'.
It is highly unlikely that 'Bernhard is a frog and Julius is a rhino'.
There is a very good chance that 'Bernhard is a frog and Julius is a rhino'.

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

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

  query(conclusion).
  
'Bernhard is a frog and Julius is a rhino'.