SEARCH Articles Figures Tables D. Lorimer and Primal de Lanerolle Duality primal problem Non-primal schemes Outer approximation primal problem Primal SDP problem Primal binary schemes Primal element Primal problem Primal substance Primal-dual Primal-dual circle representation Primal-dual interior point Primal-dual interior point algorithms Primal-dual interior point method Primality test