context: We believe that Julius is a rhino. There is a very good chance that Lily is a swan. We doubt that Greg is a frog. It is impossible that if either 'Julius is a rhino' or 'Lily is a swan' but not both then Jessica is a mouse. It is highly likely that if 'Lily is a swan and Greg is a frog' then John moved to the office. It is unlikely that if 'Lily is a swan' or 'Greg is a frog' or both then Mary put down the apple.
hypothesis: It is almost certain that 'Mary put down the apple and Greg is a frog'.
valid_hypothesis: It is highly unlikely that 'Mary put down the apple and Greg is a frog'.
invalid_hypothesis: It is almost certain that 'Mary put down the apple and Greg is a frog'.
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
    0.75::factA.
    0.8::factB.
    0.2::factC.
    %hop1
    0.0::factX:-xor(factA,factB).
    0.9::factY:-and(factB,factC).
    0.2::factZ:-or(factB,factC).
  
    %hop2
    conclusion:-and(factZ,factC).
  
    query(conclusion).
    
hypothesis_assertion: 'Mary put down the apple and Greg is a frog'.