1 p Premise 2 (~~~p => p) => ((~~~p => ~p) => ~~p) Contradiction Realization 3 p => (~~~p => p) Implication Introduction 4 ~~~p => p Modus Ponens 3 1 5 (~~~p => ~p) => ~~p Modus Ponens 2 4 6 ~~~p => ~p 33122138465.xml 7 ~~p Modus Ponens 5 6