It is likely that Antoine is hungry. It is probably not the case that Jessica is a mouse. It is probably not the case that Bernhard is a rhino. It is impossible that if 'Antoine is hungry' or 'Jessica is a mouse' or both then Greg is gray. It is impossible that if 'Bernhard is a rhino' or 'Jessica is a mouse' or both then Brian is a swan. It is almost certain that if 'Jessica is a mouse' or 'Antoine is hungry' or both then Mary moved to the office.
We believe that either 'Brian is a swan' or 'Mary moved to the office' but not both.
We believe that either 'Brian is a swan' or 'Mary moved to the office' but not both.
It is improbable that either 'Brian is a swan' or 'Mary moved to the office' 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.
  0.25::factB.
  0.25::factC.
  %hop1
  0.0::factX:-or(factA,factB).
  0.0::factY:-or(factC,factB).
  0.95::factZ:-or(factB,factA).

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

  query(conclusion).
  
Either 'Brian is a swan' or 'Mary moved to the office' but not both.