context: It is probably the case that Mary picked up the milk. There is a better than even chance that Bernhard is a rhino. It is certain that Greg is a lion.
hypothesis: Chances are about even that 'Bernhard is a rhino and Mary picked up the milk'.
valid_hypothesis: Chances are about even that 'Bernhard is a rhino and Mary picked up the milk'.
invalid_hypothesis: There is almost no chance that 'Bernhard is a rhino and Mary picked up the milk'.
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.
    0.6::factB.
    1.0::factC.
    
  
    %hop2
    conclusion:-and(factB,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Bernhard is a rhino and Mary picked up the milk'.