context: It is highly unlikely that Emily is a mouse. It is unlikely that Lily is a swan. There is a better than even chance that Daniel got the football. Chances are about even that if 'Lily is a swan and Emily is a mouse' then Sumit is thirsty. There is almost no chance that if 'Lily is a swan' or 'Daniel got the football' or both then Julius is a lion. Chances are slight that if 'Emily is a mouse' or 'Lily is a swan' or both then Brian is a rhino.
hypothesis: We doubt that 'Lily is a swan' or 'Brian is a rhino' or both.
valid_hypothesis: We doubt that 'Lily is a swan' or 'Brian is a rhino' or both.
invalid_hypothesis: It is certain that 'Lily is a swan' or 'Brian is a rhino' 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
    0.05::factA.
    0.2::factB.
    0.6::factC.
    %hop1
    0.5::factX:-and(factB,factA).
    0.02::factY:-or(factB,factC).
    0.1::factZ:-or(factA,factB).
  
    %hop2
    conclusion:-or(factB,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Lily is a swan' or 'Brian is a rhino' or both.