There is a very good chance that Bernhard is a rhino. It is highly unlikely that Mary moved to the office. It is certain that Brian is a frog. It is probably the case that if 'Bernhard is a rhino and Brian is a frog' then Jessica is a sheep. It is probable that if 'Brian is a frog and Bernhard is a rhino' then Yann is hungry. It is probably the case that if 'Bernhard is a rhino' or 'Mary moved to the office' or both then Lily is yellow.
It is likely that either 'Jessica is a sheep' or 'Lily is yellow' but not both.
It is probably not the case that either 'Jessica is a sheep' or 'Lily is yellow' but not both.
It is likely that either 'Jessica is a sheep' or 'Lily 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
  0.8::factA.
  0.05::factB.
  1.0::factC.
  %hop1
  0.7::factX:-and(factA,factC).
  0.7::factY:-and(factC,factA).
  0.7::factZ:-or(factA,factB).

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

  query(conclusion).
  
Either 'Jessica is a sheep' or 'Lily is yellow' but not both.