context: It is likely that John left the football. There is a very good chance that Brian is a swan. It is certain that Bill went to the kitchen.
hypothesis: It is certain that 'Bill went to the kitchen' or 'John left the football' or both.
valid_hypothesis: It is certain that 'Bill went to the kitchen' or 'John left the football' or both.
invalid_hypothesis: There is almost no chance that 'Bill went to the kitchen' or 'John left the football' 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
    0.7::factA.
    0.8::factB.
    1.0::factC.
    
  
    %hop2
    conclusion:-or(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Bill went to the kitchen' or 'John left the football' or both.