There is a very good chance that Bernhard is yellow. There is little chance that Lily is a rhino. There is almost no chance that Brian is a lion. There is little chance that if 'Brian is a lion' or 'Lily is a rhino' or both then Julius is a frog. It is probable that if either 'Bernhard is yellow' or 'Lily is a rhino' but not both then Greg is a swan. It is almost certain that if 'Lily is a rhino and Bernhard is yellow' then John took the football.
It is certain that either 'Lily is a rhino' or 'John took the football' but not both.
There is almost no chance that either 'Lily is a rhino' or 'John took the football' but not both.
It is certain that either 'Lily is a rhino' or 'John took the football' 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
  0.8::factA.
  0.1::factB.
  0.02::factC.
  %hop1
  0.1::factX:-or(factC,factB).
  0.7::factY:-xor(factA,factB).
  0.95::factZ:-and(factB,factA).

  %hop2
  conclusion:-xor(factB,factZ).

  query(conclusion).
  
Either 'Lily is a rhino' or 'John took the football' but not both.