context: It is almost certain that John got the apple. It is likely that Greg is a frog. It is improbable that Mary moved to the office.
hypothesis: It is highly likely that either 'Mary moved to the office' or 'John got the apple' but not both.
valid_hypothesis: It is highly likely that either 'Mary moved to the office' or 'John got the apple' but not both.
invalid_hypothesis: It is unlikely that either 'Mary moved to the office' or 'John got the apple' 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
    0.95::factA.
    0.7::factB.
    0.1::factC.
    
  
    %hop2
    conclusion:-xor(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Mary moved to the office' or 'John got the apple' but not both.