context: There is almost no chance that Greg is gray. We believe that Lily is yellow. There is a very good chance that Brian is a frog. It is likely that if either 'Brian is a frog' or 'Lily is yellow' but not both then Mary took the milk. It is almost certain that if 'Greg is gray' or 'Brian is a frog' or both then Emily is a sheep. It is improbable that if 'Greg is gray' or 'Brian is a frog' or both then Bill left the football.
hypothesis: It is almost certain that 'Lily is yellow' or 'Emily is a sheep' or both.
valid_hypothesis: It is almost certain that 'Lily is yellow' or 'Emily is a sheep' or both.
invalid_hypothesis: There is almost no chance that 'Lily is yellow' or 'Emily is a sheep' 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
    0.02::factA.
    0.75::factB.
    0.8::factC.
    %hop1
    0.7::factX:-xor(factC,factB).
    0.95::factY:-or(factA,factC).
    0.1::factZ:-or(factA,factC).
  
    %hop2
    conclusion:-or(factB,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Lily is yellow' or 'Emily is a sheep' or both.