context: It is likely that Fred put down the apple. There is little chance that Julius is a frog. It is unlikely that Mary got the football.
hypothesis: We believe that 'Fred put down the apple and Mary got the football'.
valid_hypothesis: Chances are slight that 'Fred put down the apple and Mary got the football'.
invalid_hypothesis: We believe that 'Fred put down the apple and Mary got 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
    0.7::factA.
    0.1::factB.
    0.2::factC.
    
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Fred put down the apple and Mary got the football'.