context: Chances are slight that Sandra took the milk. It is almost certain that Fred is in the school. It is unlikely that John went to the garden.
hypothesis: We doubt that 'Fred is in the school and John went to the garden'.
valid_hypothesis: We doubt that 'Fred is in the school and John went to the garden'.
invalid_hypothesis: It is almost certain that 'Fred is in the school and John went to the garden'.
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
    0.1::factA.
    0.95::factB.
    0.2::factC.
    
  
    %hop2
    conclusion:-and(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Fred is in the school and John went to the garden'.