It is highly likely that Brian is white. Chances are slight that Greg is a lion. There is a better than even chance that Bernhard is a swan. It is highly unlikely that if either 'Greg is a lion' or 'Bernhard is a swan' but not both then Sandra took the apple. It is unlikely that if 'Bernhard is a swan and Greg is a lion' then John went to the office. There is a very good chance that if 'Greg is a lion and Brian is white' then Lily is a frog.
It is probably the case that 'John went to the office and Bernhard is a swan'.
There is almost no chance that 'John went to the office and Bernhard is a swan'.
It is probably the case that 'John went to the office 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
  0.9::factA.
  0.1::factB.
  0.6::factC.
  %hop1
  0.05::factX:-xor(factB,factC).
  0.2::factY:-and(factC,factB).
  0.8::factZ:-and(factB,factA).

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

  query(conclusion).
  
'John went to the office and Bernhard is a swan'.