It is improbable that Julius is green. It is impossible that Sandra grabbed the apple. It is highly unlikely that John went to the hallway. It is probably the case that if 'Sandra grabbed the apple and John went to the hallway' then Mary left the football. It is highly unlikely that if either 'Julius is green' or 'John went to the hallway' but not both then Gertrude is a wolf. It is highly likely that if 'John went to the hallway' or 'Julius is green' or both then Brian is white.
It is probably the case that either 'John went to the hallway' or 'Gertrude is a wolf' but not both.
It is highly unlikely that either 'John went to the hallway' or 'Gertrude is a wolf' but not both.
It is probably the case that either 'John went to the hallway' or 'Gertrude is a wolf' 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
  0.1::factA.
  0.0::factB.
  0.05::factC.
  %hop1
  0.7::factX:-and(factB,factC).
  0.05::factY:-xor(factA,factC).
  0.9::factZ:-or(factC,factA).

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

  query(conclusion).
  
Either 'John went to the hallway' or 'Gertrude is a wolf' but not both.