It is almost certain that Brian is white. It is likely that Winona is a mouse. It is improbable that Mary put down the apple. It is likely that if 'Mary put down the apple and Winona is a mouse' then Bernhard is a swan. It is highly likely that if 'Brian is white and Winona is a mouse' then John moved to the garden. It is unlikely that if 'Winona is a mouse' or 'Brian is white' or both then Julius is yellow.
It is almost certain that either 'Winona is a mouse' or 'John moved to the garden' but not both.
Chances are slight that either 'Winona is a mouse' or 'John moved to the garden' but not both.
It is almost certain that either 'Winona is a mouse' or 'John moved to the garden' 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.
  0.7::factB.
  0.1::factC.
  %hop1
  0.7::factX:-and(factC,factB).
  0.9::factY:-and(factA,factB).
  0.2::factZ:-or(factB,factA).

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

  query(conclusion).
  
Either 'Winona is a mouse' or 'John moved to the garden' but not both.