There is a very good chance that Brian is green. Chances are slight that Bernhard is yellow. There is little chance that Daniel got the milk. It is highly likely that if 'Brian is green and Bernhard is yellow' then Julius is a swan. It is probably not the case that if 'Bernhard is yellow' or 'Brian is green' or both then Sandra took the football. There is a better than even chance that if 'Daniel got the milk and Bernhard is yellow' then Jeff moved to the garden.
It is probably the case that 'Brian is green and Daniel got the milk'.
It is improbable that 'Brian is green and Daniel got the milk'.
It is probably the case that 'Brian is green and Daniel got the milk'.

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

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

  query(conclusion).
  
'Brian is green and Daniel got the milk'.