context: It is impossible that Bill went to the garden. It is likely that John put down the milk. It is highly likely that Greg is white. It is impossible that if 'Greg is white' or 'John put down the milk' or both then Brian is a rhino. We believe that if 'Greg is white' or 'Bill went to the garden' or both then Julius is yellow. It is almost certain that if 'Bill went to the garden' or 'Greg is white' or both then Sandra left the milk.
hypothesis: There is almost no chance that 'John put down the milk and Greg is white'.
valid_hypothesis: There is a better than even chance that 'John put down the milk and Greg is white'.
invalid_hypothesis: There is almost no chance that 'John put down the milk 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
    0.0::factA.
    0.7::factB.
    0.9::factC.
    %hop1
    0.0::factX:-or(factC,factB).
    0.75::factY:-or(factC,factA).
    0.95::factZ:-or(factA,factC).
  
    %hop2
    conclusion:-and(factB,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'John put down the milk and Greg is white'.