It ' s sad that you ' ve made so many insults that you can ' t even keep track of which ones are being talking about . <| sep |> Hubba for 70 month ? That ' s a bargain ! Love it ! Thanks so much for that . I ' ll definitely check them out next time I ' m in town . <| sep |> Honey , what is this jar of peanut butter doing in the shower ? <| sep |> Quick question , I just managed to snag one of the new 3 ds black friday consoles and was planning to do the dsiware hax with system transfer from a cfw o 3 ds . The n 3 ds comes with 11 . 0 . 0 but the guide says if you are below 11 . 2 you should use crt Is there a reason I shouldn ' t just update the n 3 ds to 11 . 2 . 0 so I don ' t need it ? <| sep |> Hi there . So , you ' re using LPL as a reference that means you ' re using Fitch for derivations , correct ? Let ' s start with your first proof strategy . The issue I ' m having is I can ' t seem to figure out how to prove that A is a contradiction . I ' m assuming you ' re trying to derive ~ A through some sort of indirect proof , and then derive ~ A v ~ D through vIntro ? Judging from the premises , this won ' t be happening any time soon . It doesn ' t seem like you ' d be able to derive a contradiction from assuming A . However . Look at usvartsomsilver ' s commentCan you show that A D ? Remember disjunctive syllogism ? Well , this is disjunctive syllogism in disguise . Look at your conclusion if you assumed A , could you somehow derive ~ D and conclude A ~ D ? . After all , A ~ D is logically equivalent to ~ A v ~ D . Now , regarding your second proof strategy . I know I can get ~ D from assuming ~ C from conditional elimination . This would be one of the final steps in your proof . Imagine that you ' ve already assumed A . Now you have ~ B v ~ C . But you know that B is the case from the premises . So , ~ C . We know that ~ C ~ D from the premises , and so , ~ D . Now all you have to figure out is how to execute this proof strategy in Fitch . Good luck .