context: It is unlikely that Daniel left the apple. It is almost certain that John took the football. Chances are slight that Brian is gray.
hypothesis: We doubt that 'Daniel left the apple and John took the football'.
valid_hypothesis: We doubt that 'Daniel left the apple and John took the football'.
invalid_hypothesis: It is certain that 'Daniel left the apple and John took the football'.
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
    0.2::factA.
    0.95::factB.
    0.1::factC.
    
  
    %hop2
    conclusion:-and(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Daniel left the apple and John took the football'.