context: It is certain that Julius is a lion. It is improbable that Bernhard is a rhino. It is almost certain that John left the apple.
hypothesis: There is little chance that 'Julius is a lion and John left the apple'.
valid_hypothesis: It is almost certain that 'Julius is a lion and John left the apple'.
invalid_hypothesis: There is little chance that 'Julius is a lion and John left the apple'.
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
    1.0::factA.
    0.1::factB.
    0.95::factC.
    
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Julius is a lion and John left the apple'.