It is probably not the case that Brian is white. There is a better than even chance that Julius is a swan. There is almost no chance that Bernhard is a rhino. There is almost no chance that if 'Julius is a swan' or 'Bernhard is a rhino' or both then Mary left the football. It is improbable that if 'Julius is a swan' or 'Bernhard is a rhino' or both then John went to the office. There is almost no chance that if 'Julius is a swan' or 'Bernhard is a rhino' or both then Greg is a frog.
It is impossible that 'Mary left the football and Bernhard is a rhino'.
It is impossible that 'Mary left the football and Bernhard is a rhino'.
There is a better than even chance that 'Mary left the football and Bernhard 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
  0.25::factA.
  0.6::factB.
  0.02::factC.
  %hop1
  0.02::factX:-or(factB,factC).
  0.1::factY:-or(factB,factC).
  0.02::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Mary left the football and Bernhard is a rhino'.