context: There is almost no chance that Brian is yellow. Chances are about even that Mary left the milk. It is impossible that Greg is a swan.
hypothesis: Chances are about even that 'Brian is yellow' or 'Mary left the milk' or both.
valid_hypothesis: Chances are about even that 'Brian is yellow' or 'Mary left the milk' or both.
invalid_hypothesis: It is highly unlikely that 'Brian is yellow' or 'Mary left the milk' or both.
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
    0.02::factA.
    0.5::factB.
    0.0::factC.
    
  
    %hop2
    conclusion:-or(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is yellow' or 'Mary left the milk' or both.