It is probably not the case that Bernhard is a rhino. It is highly unlikely that Gertrude is a sheep. It is probably the case that Emily is a wolf. It is improbable that if 'Emily is a wolf' or 'Bernhard is a rhino' or both then Fred left the football. It is impossible that if either 'Gertrude is a sheep' or 'Bernhard is a rhino' but not both then John dropped the milk. It is improbable that if either 'Gertrude is a sheep' or 'Bernhard is a rhino' but not both then Lily is a swan.
There is a very good chance that either 'Bernhard is a rhino' or 'Lily is a swan' but not both.
It is probably not the case that either 'Bernhard is a rhino' or 'Lily is a swan' but not both.
There is a very good chance that either 'Bernhard is a rhino' or 'Lily is a swan' 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
  0.25::factA.
  0.05::factB.
  0.7::factC.
  %hop1
  0.1::factX:-or(factC,factA).
  0.0::factY:-xor(factB,factA).
  0.1::factZ:-xor(factB,factA).

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

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