context: There is a very good chance that Mary left the football. It is impossible that Jessica is a sheep. It is certain that Julius is white.
hypothesis: There is a very good chance that 'Mary left the football and Julius is white'.
valid_hypothesis: There is a very good chance that 'Mary left the football and Julius is white'.
invalid_hypothesis: Chances are slight that 'Mary left the football and Julius is white'.
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
    0.8::factA.
    0.0::factB.
    1.0::factC.
    
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary left the football and Julius is white'.