context: There is a better than even chance that Gertrude is a cat. It is probably not the case that Sandra grabbed the apple. It is certain that Mary went to the garden.
hypothesis: It is highly likely that 'Gertrude is a cat and Sandra grabbed the apple'.
valid_hypothesis: Chances are slight that 'Gertrude is a cat and Sandra grabbed the apple'.
invalid_hypothesis: It is highly likely that 'Gertrude is a cat and Sandra grabbed the apple'.
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
    0.6::factA.
    0.25::factB.
    1.0::factC.
    
  
    %hop2
    conclusion:-and(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Gertrude is a cat and Sandra grabbed the apple'.