It is probably the case that Bernhard is a swan. It is almost certain that Brian is green. There is a better than even chance that John picked up the milk. Chances are slight that if either 'Bernhard is a swan' or 'John picked up the milk' but not both then Winona is a cat. It is highly likely that if either 'Brian is green' or 'John picked up the milk' but not both then Julius is a frog. We believe that if 'Bernhard is a swan and Brian is green' then Greg is yellow.
It is highly unlikely that 'John picked up the milk and Bernhard is a swan'.
Chances are about even that 'John picked up the milk and Bernhard is a swan'.
It is highly unlikely that 'John picked up the milk and Bernhard 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
  0.7::factA.
  0.95::factB.
  0.6::factC.
  %hop1
  0.1::factX:-xor(factA,factC).
  0.9::factY:-xor(factB,factC).
  0.75::factZ:-and(factA,factB).

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

  query(conclusion).
  
'John picked up the milk and Bernhard is a swan'.