It is impossible that Yann is tired. It is probably the case that John went to the hallway. It is probable that Daniel grabbed the milk. It is highly unlikely that if either 'Yann is tired' or 'John went to the hallway' but not both then Lily is white. We doubt that if 'Daniel grabbed the milk' or 'Yann is tired' or both then Julius is gray. It is impossible that if 'John went to the hallway' or 'Daniel grabbed the milk' or both then Brian is yellow.
It is impossible that 'Daniel grabbed the milk and Brian is yellow'.
It is impossible that 'Daniel grabbed the milk and Brian is yellow'.
It is almost certain that 'Daniel grabbed the milk and Brian is yellow'.

  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
  0.0::factA.
  0.7::factB.
  0.7::factC.
  %hop1
  0.05::factX:-xor(factA,factB).
  0.2::factY:-or(factC,factA).
  0.0::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Daniel grabbed the milk and Brian is yellow'.