It is impossible that Mary went to the hallway. It is probable that Greg is white. It is probably not the case that Bernhard is a frog. We believe that if 'Mary went to the hallway' or 'Bernhard is a frog' or both then Emily is a wolf. It is highly likely that if either 'Bernhard is a frog' or 'Mary went to the hallway' but not both then Brian is a rhino. It is impossible that if 'Mary went to the hallway and Bernhard is a frog' then John moved to the garden.
There is almost no chance that either 'Bernhard is a frog' or 'Brian is a rhino' but not both.
There is almost no chance that either 'Bernhard is a frog' or 'Brian is a rhino' but not both.
It is probably the case that either 'Bernhard is a frog' or 'Brian 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
  0.0::factA.
  0.7::factB.
  0.25::factC.
  %hop1
  0.75::factX:-or(factA,factC).
  0.9::factY:-xor(factC,factA).
  0.0::factZ:-and(factA,factC).

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

  query(conclusion).
  
Either 'Bernhard is a frog' or 'Brian is a rhino' but not both.