context: It is highly likely that Lily is a rhino. Chances are slight that Winona is a sheep. It is highly unlikely that John went to the office. It is probably not the case that if either 'Lily is a rhino' or 'Winona is a sheep' but not both then Bernhard is a frog. It is unlikely that if 'Lily is a rhino' or 'Winona is a sheep' or both then Brian is a lion. It is likely that if either 'John went to the office' or 'Winona is a sheep' but not both then Mary left the milk.
hypothesis: It is highly likely that 'Brian is a lion' or 'Mary left the milk' or both.
valid_hypothesis: It is probably not the case that 'Brian is a lion' or 'Mary left the milk' or both.
invalid_hypothesis: It is highly likely that 'Brian is a lion' or 'Mary left the milk' 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
    0.9::factA.
    0.1::factB.
    0.05::factC.
    %hop1
    0.25::factX:-xor(factA,factB).
    0.2::factY:-or(factA,factB).
    0.7::factZ:-xor(factC,factB).
  
    %hop2
    conclusion:-or(factY,factZ).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is a lion' or 'Mary left the milk' or both.