context: It is impossible that Winona is a cat. It is probably the case that Lily is a frog. There is a very good chance that Jessica is a sheep. It is likely that if 'Lily is a frog and Winona is a cat' then Brian is green. Chances are slight that if either 'Lily is a frog' or 'Jessica is a sheep' but not both then Bernhard is a lion. It is likely that if either 'Lily is a frog' or 'Winona is a cat' but not both then John went to the hallway.
hypothesis: It is impossible that 'Jessica is a sheep and Brian is green'.
valid_hypothesis: It is impossible that 'Jessica is a sheep and Brian is green'.
invalid_hypothesis: It is certain that 'Jessica is a sheep and Brian is green'.
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
    0.0::factA.
    0.7::factB.
    0.8::factC.
    %hop1
    0.7::factX:-and(factB,factA).
    0.1::factY:-xor(factB,factC).
    0.7::factZ:-xor(factB,factA).
  
    %hop2
    conclusion:-and(factC,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'Jessica is a sheep and Brian is green'.