context: It is highly likely that Bernhard is yellow. It is certain that Gertrude is a cat. There is almost no chance that John moved to the office. We believe that if either 'Bernhard is yellow' or 'Gertrude is a cat' but not both then Julius is a swan. It is improbable that if either 'John moved to the office' or 'Bernhard is yellow' but not both then Lily is a frog. It is probably the case that if 'John moved to the office' or 'Gertrude is a cat' or both then Sumit is bored.
hypothesis: It is probably the case that either 'John moved to the office' or 'Julius is a swan' but not both.
valid_hypothesis: It is improbable that either 'John moved to the office' or 'Julius is a swan' but not both.
invalid_hypothesis: It is probably the case that either 'John moved to the office' or 'Julius is a swan' but not both.
problog: 
    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
    0.9::factA.
    1.0::factB.
    0.02::factC.
    %hop1
    0.75::factX:-xor(factA,factB).
    0.1::factY:-xor(factC,factA).
    0.7::factZ:-or(factC,factB).
  
    %hop2
    conclusion:-xor(factC,factX).
  
    query(conclusion).
    
hypothesis_assertion: Either 'John moved to the office' or 'Julius is a swan' but not both.