context: It is highly unlikely that Mary left the apple. Chances are slight that Julius is gray. It is improbable that Jeff went to the garden. There is a very good chance that if 'Julius is gray' or 'Jeff went to the garden' or both then Lily is yellow. Chances are about even that if 'Julius is gray' or 'Mary left the apple' or both then Brian is a frog. Chances are about even that if 'Julius is gray and Mary left the apple' then Sumit is thirsty.
hypothesis: It is likely that 'Sumit is thirsty and Lily is yellow'.
valid_hypothesis: It is impossible that 'Sumit is thirsty and Lily is yellow'.
invalid_hypothesis: It is likely that 'Sumit is thirsty and Lily is yellow'.
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.
    0.1::factB.
    0.1::factC.
    %hop1
    0.8::factX:-or(factB,factC).
    0.5::factY:-or(factB,factA).
    0.5::factZ:-and(factB,factA).
  
    %hop2
    conclusion:-and(factZ,factX).
  
    query(conclusion).
    
hypothesis_assertion: 'Sumit is thirsty and Lily is yellow'.