context: It is highly likely that Daniel took the apple. There is a very good chance that Brian is a frog. It is certain that Greg is white. It is improbable that if 'Brian is a frog' or 'Daniel took the apple' or both then John went to the garden. Chances are about even that if either 'Brian is a frog' or 'Greg is white' but not both then Lily is a lion. It is almost certain that if 'Brian is a frog' or 'Greg is white' or both then Julius is green.
hypothesis: It is almost certain that 'Julius is green and Greg is white'.
valid_hypothesis: It is almost certain that 'Julius is green and Greg is white'.
invalid_hypothesis: There is little chance that 'Julius is green and Greg is white'.
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.
    0.8::factB.
    1.0::factC.
    %hop1
    0.1::factX:-or(factB,factA).
    0.5::factY:-xor(factB,factC).
    0.95::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-and(factZ,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Julius is green and Greg is white'.