context: It is highly unlikely that Brian is white. It is almost certain that Lily is a lion. There is a better than even chance that John went to the garden. Chances are slight that if 'Lily is a lion' or 'Brian is white' or both then Sandra got the milk. There is little chance that if either 'Lily is a lion' or 'Brian is white' but not both then Julius is gray. It is likely that if 'Lily is a lion' or 'John went to the garden' or both then Jessica is a wolf.
hypothesis: It is probably the case that 'Brian is white' or 'Julius is gray' or both.
valid_hypothesis: Chances are slight that 'Brian is white' or 'Julius is gray' or both.
invalid_hypothesis: It is probably the case that 'Brian is white' or 'Julius is gray' 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.
    0.95::factB.
    0.6::factC.
    %hop1
    0.1::factX:-or(factB,factA).
    0.1::factY:-xor(factB,factA).
    0.7::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-or(factA,factY).
  
    query(conclusion).
    
hypothesis_assertion: 'Brian is white' or 'Julius is gray' or both.