- The goal is to show that, for a European put with maturity T >t, the condition Pt) > max(E e- (T-t) s(t),O) is arbitrage-free. Use the definition of an arbitrage portfolio, and prove the contrapositive. That is, show that if P(t) 0. Assume that Pt) 0, then V(T) >0. - The goal is to show that, for a European put with maturity T >t, the condition Pt) > max(E e- (T-t) s(t),O) is arbitrage-free. Use the definition of an arbitrage portfolio, and prove the contrapositive. That is, show that if P(t) 0. Assume that Pt) 0, then V(T) >0