It is probably not the case that Julius is yellow. There is almost no chance that Emily is a wolf. There is a better than even chance that Brian is a lion. Chances are about even that if 'Brian is a lion and Emily is a wolf' then Bernhard is green. There is a very good chance that if 'Emily is a wolf' or 'Julius is yellow' or both then Mary left the milk. It is highly unlikely that if 'Brian is a lion' or 'Julius is yellow' or both then John went to the office.
It is impossible that 'Brian is a lion and Bernhard is green'.
It is impossible that 'Brian is a lion and Bernhard is green'.
We believe that 'Brian is a lion and Bernhard is green'.

  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.
  0.02::factB.
  0.6::factC.
  %hop1
  0.5::factX:-and(factC,factB).
  0.8::factY:-or(factB,factA).
  0.05::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Brian is a lion and Bernhard is green'.