It is impossible that Bernhard is yellow. It is improbable that Julius is a lion. It is probably the case that Mary went to the office. It is highly unlikely that if either 'Mary went to the office' or 'Julius is a lion' but not both then Brian is gray. It is probable that if 'Julius is a lion' or 'Bernhard is yellow' or both then Lily is white. There is a better than even chance that if 'Mary went to the office' or 'Julius is a lion' or both then Greg is green.
It is probably not the case that 'Mary went to the office' or 'Julius is a lion' or both.
We believe that 'Mary went to the office' or 'Julius is a lion' or both.
It is probably not the case that 'Mary went to the office' 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
  0.0::factA.
  0.1::factB.
  0.7::factC.
  %hop1
  0.05::factX:-xor(factC,factB).
  0.7::factY:-or(factB,factA).
  0.6::factZ:-or(factC,factB).

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

  query(conclusion).
  
'Mary went to the office' or 'Julius is a lion' or both.