context: Chances are slight that John went to the office. It is highly likely that Gertrude is a cat. We doubt that Greg is a lion.
hypothesis: It is highly likely that 'John went to the office and Greg is a lion'.
valid_hypothesis: There is almost no chance that 'John went to the office and Greg is a lion'.
invalid_hypothesis: It is highly likely that 'John went to the office and Greg is a lion'.
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
    0.1::factA.
    0.9::factB.
    0.2::factC.
    
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'John went to the office and Greg is a lion'.