It is certain that Bernhard is green. It is probably not the case that Yann is bored. Chances are slight that Mary went to the office. It is highly unlikely that if 'Bernhard is green' or 'Mary went to the office' or both then Lily is white. It is certain that if 'Bernhard is green' or 'Mary went to the office' or both then Julius is a lion. There is almost no chance that if 'Mary went to the office and Bernhard is green' then John dropped the milk.
It is certain that 'Bernhard is green' or 'Julius is a lion' or both.
It is certain that 'Bernhard is green' or 'Julius is a lion' or both.
There is almost no chance that 'Bernhard is green' or 'Julius is a lion' or both.

  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
  1.0::factA.
  0.25::factB.
  0.1::factC.
  %hop1
  0.05::factX:-or(factA,factC).
  1.0::factY:-or(factA,factC).
  0.02::factZ:-and(factC,factA).

  %hop2
  conclusion:-or(factA,factY).

  query(conclusion).
  
'Bernhard is green' or 'Julius is a lion' or both.