Theorem 2 (Strong Duality). Under the same ( ρ , ψ , d ) -quasiinvexity hypotheses formulated in Theorem 1, if ( a 0 , u 0 ) ∈ D is a normal LU-efficient solution of the Primal Problem ( P P ) , then there exist θ 0 , μ 0 ( t ) and λ 0 ( t ) such that ...