context: There is almost no chance that John dropped the apple. Chances are slight that Julius is a swan. There is a better than even chance that Fred went to the garden.
hypothesis: It is certain that 'Fred went to the garden and Julius is a swan'.
valid_hypothesis: It is highly unlikely that 'Fred went to the garden and Julius is a swan'.
invalid_hypothesis: It is certain that 'Fred went to the garden and Julius is a swan'.
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.
    0.1::factB.
    0.6::factC.
    
  
    %hop2
    conclusion:-and(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Fred went to the garden and Julius is a swan'.