context: We doubt that John took the apple. It is almost certain that Emily is a sheep. Chances are about even that Mary left the milk.
hypothesis: Chances are about even that 'Mary left the milk and Emily is a sheep'.
valid_hypothesis: Chances are about even that 'Mary left the milk and Emily is a sheep'.
invalid_hypothesis: It is highly unlikely that 'Mary left the milk and Emily is a sheep'.
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
    0.2::factA.
    0.95::factB.
    0.5::factC.
    
  
    %hop2
    conclusion:-and(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary left the milk and Emily is a sheep'.