context: It is unlikely that John went to the office. There is a very good chance that Julius is a frog. It is certain that Greg is green.
hypothesis: It is likely that 'John went to the office and Greg is green'.
valid_hypothesis: We doubt that 'John went to the office and Greg is green'.
invalid_hypothesis: It is likely that 'John went to the office and Greg 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
    0.2::factA.
    0.8::factB.
    1.0::factC.
    
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'John went to the office and Greg is green'.