context: It is unlikely that Brian is yellow. Chances are about even that Greg is white. Chances are slight that Jessica is a cat. It is almost certain that if either 'Greg is white' or 'Jessica is a cat' but not both then Mary left the milk. Chances are about even that if 'Greg is white and Jessica is a cat' then Lily is a lion. It is almost certain that if 'Greg is white' or 'Jessica is a cat' or both then John went to the office.
hypothesis: It is highly unlikely that 'Lily is a lion' or 'Greg is white' or both.
valid_hypothesis: Chances are about even that 'Lily is a lion' or 'Greg is white' or both.
invalid_hypothesis: It is highly unlikely that 'Lily is a lion' or 'Greg is white' 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
    0.2::factA.
    0.5::factB.
    0.1::factC.
    %hop1
    0.95::factX:-xor(factB,factC).
    0.5::factY:-and(factB,factC).
    0.95::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-or(factY,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Lily is a lion' or 'Greg is white' or both.