It is highly likely that Julius is yellow. It is improbable that Bernhard is a frog. It is highly likely that Daniel got the football. There is almost no chance that if either 'Daniel got the football' or 'Bernhard is a frog' but not both then Greg is a lion. There is a better than even chance that if 'Daniel got the football and Julius is yellow' then Brian is a rhino. Chances are about even that if 'Bernhard is a frog' or 'Julius is yellow' or both then Lily is white.
It is highly likely that either 'Greg is a lion' or 'Julius is yellow' but not both.
It is highly likely that either 'Greg is a lion' or 'Julius is yellow' but not both.
Chances are slight that either 'Greg is a lion' or 'Julius is yellow' but not 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
  0.9::factA.
  0.1::factB.
  0.9::factC.
  %hop1
  0.02::factX:-xor(factC,factB).
  0.6::factY:-and(factC,factA).
  0.5::factZ:-or(factB,factA).

  %hop2
  conclusion:-xor(factX,factA).

  query(conclusion).
  
Either 'Greg is a lion' or 'Julius is yellow' but not both.