context: There is almost no chance that Mary went to the office. It is probably not the case that Sumit is tired. It is probably the case that John dropped the apple.
hypothesis: Chances are slight that either 'Mary went to the office' or 'John dropped the apple' but not both.
valid_hypothesis: It is probable that either 'Mary went to the office' or 'John dropped the apple' but not both.
invalid_hypothesis: Chances are slight that either 'Mary went to the office' or 'John dropped 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
    0.02::factA.
    0.25::factB.
    0.7::factC.
    
  
    %hop2
    conclusion:-xor(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Mary went to the office' or 'John dropped the apple' but not both.