context: There is almost no chance that Mary left the football. We doubt that Lily is green. There is little chance that Greg is gray.
hypothesis: It is impossible that 'Mary left the football and Lily is green'.
valid_hypothesis: It is impossible that 'Mary left the football and Lily is green'.
invalid_hypothesis: It is likely that 'Mary left the football and Lily is green'.
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.
    0.2::factB.
    0.1::factC.
    
  
    %hop2
    conclusion:-and(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary left the football and Lily is green'.