context: It is probably not the case that John picked up the milk. It is improbable that Greg is a swan. There is a better than even chance that Lily is a lion. It is almost certain that if 'Lily is a lion' or 'John picked up the milk' or both then Jason is thirsty. There is a better than even chance that if either 'John picked up the milk' or 'Greg is a swan' but not both then Julius is a frog. It is probable that if 'Lily is a lion and John picked up the milk' then Brian is green.
hypothesis: There is little chance that 'Lily is a lion' or 'John picked up the milk' or both.
valid_hypothesis: It is likely that 'Lily is a lion' or 'John picked up the milk' or both.
invalid_hypothesis: There is little chance that 'Lily is a lion' or 'John picked up 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
    0.25::factA.
    0.1::factB.
    0.6::factC.
    %hop1
    0.95::factX:-or(factC,factA).
    0.6::factY:-xor(factA,factB).
    0.7::factZ:-and(factC,factA).
  
    %hop2
    conclusion:-or(factC,factA).
  
    query(conclusion).
    
hypothesis_assertion: 'Lily is a lion' or 'John picked up the milk' or both.