Yes , that proof is inconclusive . It ' s an argument by prestigious jargon hiding under the operator , that indeed means possibly true in logic , but is actually a far stronger assumption than what our common intuition of possibility would lead us to think . The argument is flawed in several steps that are very dubious by logical standards but more importantly when formally written , it ' s premisse is not only inadmissible , it is directely proven wrong by Gdel ' s theorem . <| sep |> Do your deaf friendscolleagues know you are trying to teach ? Where is your curriculum from ? Are you licensed to teach ASL ? I know I just met you , but you should be aware it ' s generally frowned upon for hearing especially non native folks to teach .