Chances are about even that Yann is bored. There is a better than even chance that Brian is green. Chances are slight that Julius is gray. It is probably the case that if 'Julius is gray' or 'Brian is green' or both then Mary dropped the milk. There is almost no chance that if 'Yann is bored and Julius is gray' then Bernhard is yellow. It is almost certain that if 'Julius is gray and Yann is bored' then Emily is a wolf.
There is a better than even chance that 'Mary dropped the milk' or 'Brian is green' or both.
There is a better than even chance that 'Mary dropped the milk' or 'Brian is green' or both.
It is highly unlikely that 'Mary dropped the milk' or 'Brian is green' 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
  0.5::factA.
  0.6::factB.
  0.1::factC.
  %hop1
  0.7::factX:-or(factC,factB).
  0.02::factY:-and(factA,factC).
  0.95::factZ:-and(factC,factA).

  %hop2
  conclusion:-or(factX,factB).

  query(conclusion).
  
'Mary dropped the milk' or 'Brian is green' or both.