It is likely that Lily is a rhino. Chances are about even that Greg is a lion. We believe that Sandra dropped the milk. Chances are about even that if 'Greg is a lion and Sandra dropped the milk' then Julius is white. It is likely that if either 'Lily is a rhino' or 'Sandra dropped the milk' but not both then Bernhard is white. Chances are about even that if either 'Sandra dropped the milk' or 'Lily is a rhino' but not both then Brian is green.
We believe that either 'Lily is a rhino' or 'Bernhard is white' but not both.
We believe that either 'Lily is a rhino' or 'Bernhard is white' but not both.
There is little chance that either 'Lily is a rhino' or 'Bernhard is white' 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
  0.7::factA.
  0.5::factB.
  0.75::factC.
  %hop1
  0.5::factX:-and(factB,factC).
  0.7::factY:-xor(factA,factC).
  0.5::factZ:-xor(factC,factA).

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

  query(conclusion).
  
Either 'Lily is a rhino' or 'Bernhard is white' but not both.