context: It is probably the case that Emily is a cat. We doubt that Lily is a rhino. It is almost certain that Greg is a swan.
hypothesis: We doubt that 'Greg is a swan and Emily is a cat'.
valid_hypothesis: It is probable that 'Greg is a swan and Emily is a cat'.
invalid_hypothesis: We doubt that 'Greg is a swan and Emily is a cat'.
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
    0.7::factA.
    0.2::factB.
    0.95::factC.
    
  
    %hop2
    conclusion:-and(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Greg is a swan and Emily is a cat'.