context: There is almost no chance that Mary got the football. Chances are slight that Yann is tired. It is likely that Greg is white.
hypothesis: We believe that 'Greg is white and Mary got the football'.
valid_hypothesis: There is almost no chance that 'Greg is white and Mary got the football'.
invalid_hypothesis: We believe that 'Greg is white 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
    0.02::factA.
    0.1::factB.
    0.7::factC.
    
  
    %hop2
    conclusion:-and(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Greg is white and Mary got the football'.