context: It is improbable that Mary dropped the apple. There is little chance that Lily is white. There is a better than even chance that John got the apple.
hypothesis: It is highly unlikely that 'Mary dropped the apple and John got the apple'.
valid_hypothesis: It is highly unlikely that 'Mary dropped the apple and John got the apple'.
invalid_hypothesis: It is almost certain that 'Mary dropped the apple and John got 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
    0.1::factA.
    0.1::factB.
    0.6::factC.
    
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary dropped the apple and John got the apple'.