context: It is highly likely that John moved to the office. It is probably the case that Greg is a frog. There is a better than even chance that Bill got the milk there.
hypothesis: It is impossible that 'John moved to the office' or 'Greg is a frog' or both.
valid_hypothesis: It is almost certain that 'John moved to the office' or 'Greg is a frog' or both.
invalid_hypothesis: It is impossible that 'John moved to the office' or 'Greg is a frog' or 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.
    0.7::factB.
    0.6::factC.
    
  
    %hop2
    conclusion:-or(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'John moved to the office' or 'Greg is a frog' or both.