Chances are slight that John went to the kitchen. There is a very good chance that Bernhard is green. It is almost certain that Julius is a swan. There is a very good chance that if 'Julius is a swan and John went to the kitchen' then Daniel got the milk. Chances are slight that if either 'John went to the kitchen' or 'Julius is a swan' but not both then Lily is a frog. It is impossible that if 'Julius is a swan' or 'Bernhard is green' or both then Mary moved to the garden.
We believe that 'Bernhard is green and Lily is a frog'.
It is highly unlikely that 'Bernhard is green and Lily is a frog'.
We believe that 'Bernhard is green and Lily is a frog'.

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

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

  query(conclusion).
  
'Bernhard is green and Lily is a frog'.