It is probably not the case that Lily is gray. It is improbable that Julius is a frog. There is a very good chance that Jeff went to the hallway. It is almost certain that if either 'Lily is gray' or 'Julius is a frog' but not both then Mary left the football. It is unlikely that if either 'Jeff went to the hallway' or 'Lily is gray' but not both then John moved to the office. It is impossible that if 'Jeff went to the hallway' or 'Julius is a frog' or both then Bernhard is green.
There is a very good chance that 'Jeff went to the hallway' or 'Bernhard is green' or both.
There is a very good chance that 'Jeff went to the hallway' or 'Bernhard is green' or both.
It is improbable that 'Jeff went to the hallway' or 'Bernhard 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
  0.25::factA.
  0.1::factB.
  0.8::factC.
  %hop1
  0.95::factX:-xor(factA,factB).
  0.2::factY:-xor(factC,factA).
  0.0::factZ:-or(factC,factB).

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

  query(conclusion).
  
'Jeff went to the hallway' or 'Bernhard is green' or both.