context: There is little chance that Lily is a rhino. We doubt that Sumit is thirsty. Chances are about even that Brian is green. It is certain that if 'Brian is green and Sumit is thirsty' then Julius is gray. It is almost certain that if either 'Brian is green' or 'Sumit is thirsty' but not both then Sandra got the football. There is almost no chance that if 'Sumit is thirsty and Lily is a rhino' then Yann is tired.
hypothesis: It is highly likely that 'Brian is green and Sumit is thirsty'.
valid_hypothesis: Chances are slight that 'Brian is green and Sumit is thirsty'.
invalid_hypothesis: It is highly likely that 'Brian is green and Sumit is thirsty'.
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.
    0.2::factB.
    0.5::factC.
    %hop1
    1.0::factX:-and(factC,factB).
    0.95::factY:-xor(factC,factB).
    0.02::factZ:-and(factB,factA).
  
    %hop2
    conclusion:-and(factC,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is green and Sumit is thirsty'.