It is almost certain that Gertrude is a sheep. It is probably not the case that Brian is a lion. It is highly likely that Mary got the football. It is highly likely that if 'Gertrude is a sheep' or 'Brian is a lion' or both then Greg is gray. It is probably not the case that if 'Gertrude is a sheep and Mary got the football' then Bernhard is a rhino. There is a very good chance that if 'Brian is a lion and Gertrude is a sheep' then John took the apple.
It is likely that either 'John took the apple' or 'Bernhard is a rhino' but not both.
It is probably not the case that either 'John took the apple' or 'Bernhard is a rhino' but not both.
It is likely that either 'John took the apple' or 'Bernhard is a rhino' 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
  0.95::factA.
  0.25::factB.
  0.9::factC.
  %hop1
  0.9::factX:-or(factA,factB).
  0.25::factY:-and(factA,factC).
  0.8::factZ:-and(factB,factA).

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

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