context: It is probably not the case that Jeff discarded the milk. It is highly likely that Bernhard is gray. It is probably the case that John got the apple.
hypothesis: There is almost no chance that 'Bernhard is gray' or 'John got the apple' or both.
valid_hypothesis: It is almost certain that 'Bernhard is gray' or 'John got the apple' or both.
invalid_hypothesis: There is almost no chance that 'Bernhard is gray' or 'John got the apple' 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
    0.25::factA.
    0.9::factB.
    0.7::factC.
    
  
    %hop2
    conclusion:-or(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is gray' or 'John got the apple' or both.