context: It is highly unlikely that Winona is a wolf. Chances are about even that Brian is a swan. It is highly unlikely that John moved to the office. There is a very good chance that if 'Brian is a swan' or 'John moved to the office' or both then Antoine is bored. Chances are about even that if 'Winona is a wolf' or 'John moved to the office' or both then Mary went to the office. There is little chance that if 'John moved to the office and Winona is a wolf' then Jason is tired.
hypothesis: It is likely that either 'Mary went to the office' or 'Winona is a wolf' but not both.
valid_hypothesis: It is highly unlikely that either 'Mary went to the office' or 'Winona is a wolf' but not both.
invalid_hypothesis: It is likely that either 'Mary went to the office' or 'Winona is a wolf' 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
    0.05::factA.
    0.5::factB.
    0.05::factC.
    %hop1
    0.8::factX:-or(factB,factC).
    0.5::factY:-or(factA,factC).
    0.1::factZ:-and(factC,factA).
  
    %hop2
    conclusion:-xor(factY,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Mary went to the office' or 'Winona is a wolf' but not both.