It is probably the case that Brian is a frog. There is almost no chance that Lily is green. It is probably not the case that Yann is tired. It is certain that if 'Yann is tired' or 'Lily is green' or both then Julius is white. It is improbable that if either 'Brian is a frog' or 'Yann is tired' but not both then John got the apple. It is almost certain that if 'Yann is tired and Lily is green' then Mary went to the kitchen.
It is likely that either 'Brian is a frog' or 'Lily is green' but not both.
It is likely that either 'Brian is a frog' or 'Lily is green' but not both.
There is almost no chance that either 'Brian is a frog' or 'Lily is green' 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.
  0.02::factB.
  0.25::factC.
  %hop1
  1.0::factX:-or(factC,factB).
  0.1::factY:-xor(factA,factC).
  0.95::factZ:-and(factC,factB).

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

  query(conclusion).
  
Either 'Brian is a frog' or 'Lily is green' but not both.