It is probable that Daniel left the football. There is a better than even chance that Brian is a rhino. Chances are about even that Bernhard is gray. There is little chance that if either 'Bernhard is gray' or 'Brian is a rhino' but not both then Greg is a lion. It is certain that if 'Brian is a rhino' or 'Bernhard is gray' or both then Lily is a frog. It is improbable that if 'Bernhard is gray' or 'Daniel left the football' or both then Julius is white.
Chances are about even that 'Bernhard is gray' or 'Greg is a lion' or both.
Chances are about even that 'Bernhard is gray' or 'Greg is a lion' or both.
There is almost no chance that 'Bernhard is gray' or 'Greg 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
  0.7::factA.
  0.6::factB.
  0.5::factC.
  %hop1
  0.1::factX:-xor(factC,factB).
  1.0::factY:-or(factB,factC).
  0.1::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Bernhard is gray' or 'Greg is a lion' or both.