context: Chances are about even that Brian is a frog. It is certain that Bernhard is a swan. It is probably the case that Jeff went to the bedroom.
hypothesis: It is likely that 'Bernhard is a swan and Jeff went to the bedroom'.
valid_hypothesis: It is likely that 'Bernhard is a swan and Jeff went to the bedroom'.
invalid_hypothesis: There is almost no chance that 'Bernhard is a swan and Jeff went to the bedroom'.
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
    0.5::factA.
    1.0::factB.
    0.7::factC.
    
  
    %hop2
    conclusion:-and(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is a swan and Jeff went to the bedroom'.