There is a better than even chance that Mary went to the garden. It is highly likely that Julius is gray. There is a very good chance that Jason is tired. There is almost no chance that if 'Jason is tired and Mary went to the garden' then Lily is a frog. There is a very good chance that if either 'Julius is gray' or 'Jason is tired' but not both then Bernhard is green. We believe that if either 'Mary went to the garden' or 'Julius is gray' but not both then Brian is white.
It is impossible that either 'Jason is tired' or 'Bernhard is green' but not both.
It is highly likely that either 'Jason is tired' or 'Bernhard is green' but not both.
It is impossible that either 'Jason is tired' or 'Bernhard 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
  0.6::factA.
  0.9::factB.
  0.8::factC.
  %hop1
  0.02::factX:-and(factC,factA).
  0.8::factY:-xor(factB,factC).
  0.75::factZ:-xor(factA,factB).

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

  query(conclusion).
  
Either 'Jason is tired' or 'Bernhard is green' but not both.