context: It is probably the case that Mary put down the milk. It is certain that John left the football. We doubt that Bernhard is gray.
hypothesis: It is certain that 'Mary put down the milk and Bernhard is gray'.
valid_hypothesis: Chances are slight that 'Mary put down the milk and Bernhard is gray'.
invalid_hypothesis: It is certain that 'Mary put down the milk and Bernhard is gray'.
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.
    1.0::factB.
    0.2::factC.
    
  
    %hop2
    conclusion:-and(factA,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary put down the milk and Bernhard is gray'.