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Linear equations and inequalities on finite dimensional, real or complex, vector spaces: a unified theory. (English) Zbl 0174.31502

This paper presents a unified theory of linear equations and inequalities, real or complex, on finite-dimensional vector spaces. Notations: Let \(S\subset \mathbb C^n\) be a closed convex cone, \[ S^*= \{y\in\mathbb C^n : x\in S\Rightarrow \text{Re}(y^Hx)\ge 0\},\ A\in \mathbb C^{m\times m}, b\in \mathbb C^m. \] The system \((*)\) \(Ax = b\), \(x\in S\) is “consistent” [ “asymptotically consistent” ] if \(\exists\, x \in S \ni Ax = b\) [ \(\exists\, \{x_k\}\subset S \ni \lim Ax_k = b\) ]. Sample results:
Theorem: The following are equivalent (where \(A^T, A^H, A^+\) denote the transpose, the conjugate transpose, the generalized inverse of \(A\))::
(a) \((*)\) is asymptotically consistent,
(b) \(A^H y\in S^* \Rightarrow \text{Re}(b^H y)\ge 0\),
(c) \(b\in R(A)\) and \(A^+ b\in \text{cl}(N(A) + S)\).
Corollary: Let \(N(A)+S\) be closed. Then \((*)\) is consistent if, and only if, \(A^H y\in S^* \Rightarrow \text{Re}(b^H y) = 0\).
Corollary (Solvability of linear equations): \(Ax = b\) is consistent if, and only if, \(A^H y = 0 \Rightarrow b^H y = 0\).
Corollary (Farkas): Let \(A\in \mathbb R^{n\times n}\), \(b\in\mathbb R^n\). Then \(Ax =b\), \(x \ge 0\) is consistent if, and only if, \(A^T y\ge 0 \Rightarrow b^T y\ge 0\).
These results are used to prove a duality theorem for complex linear programming, following and slightly extending N. Levinson [J. Math Anal. Appl. 14, 44–62 (1966; Zbl 0136.13802)].

MSC:

15A06 Linear equations (linear algebraic aspects)
15A03 Vector spaces, linear dependence, rank, lineability
90C46 Optimality conditions and duality in mathematical programming
90C05 Linear programming

Citations:

Zbl 0136.13802
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References:

[1] Beckenbach, E.F; Bellman, R, Inequalities, (1965), Springer-Verlag New York · Zbl 0128.27401
[2] Ben-Israel, A, Notes on linear inequalities, I: the intersection of the nonnegative orthant with complementary orthogonal subspaces, J. math. anal. appl., 10, 303-314, (1964) · Zbl 0141.17401
[3] Ben-Israel, A; Charnes, A, Contributions to the theory of generalized inverses, J. soc. indust. appl. math., 11, 667-699, (1963) · Zbl 0116.32202
[4] Ben-Israel, A; Charnes, A, On the intersections of cones and subspaces, Bull. amer. math. soc., 74, 541-544, (1968) · Zbl 0159.41501
[5] Ben-Israel, A; Charnes, A; Kortanek, K.O, Duality and asymptotic solvability over cones, Bull. amer. math. soc., 75, 318-324, (1969) · Zbl 0187.17504
[6] Braunschweiger, C.C; Clark, H.E, An extension of the farkas theorem, Amer. math. monthly, 69, 272-276, (1962) · Zbl 0116.08302
[7] Braunschweiger, C.C, An extension of the nonhomogeneous farkas theorem, Amer. math. monthly, 69, 969-975, (1962) · Zbl 0108.10702
[8] Černikov, S.N; Černikov, S.N, Systems of linear inequalities, Uspehi mat. nauk, Amer. math. soc. transl. ser. 2, 26, 11-86, (1963), English translation:
[9] C̆ernikov, S.N; C̆ernikov, S.N, Algebraic theory of linear inequalities, Doklady akad. nauk SSSR, Soviet math. doklady, 7, 1019-1023, (1966), English translation: · Zbl 0196.30001
[10] Charnes, A; Cooper, W.W, The strong Minkowski-farkas-Weyl theorem for vector spaces over ordered fields, (), 914-916 · Zbl 0202.03501
[11] Desoer, C.A; Whalen, B.H, A note on pseudoinverses, J. soc. indust. appl. math., 11, 442-447, (1963) · Zbl 0123.09603
[12] Deutsch, F.R; Maserick, P.H, Applications of the Hahn-Banach theorem in approximation theory, SIAM review, 9, 516-530, (1967) · Zbl 0166.10501
[13] Duffin, R.J; Peterson, E.L; Zener, C, Geometric programming—theory and application, (1967), Wiley New York · Zbl 0171.17601
[14] Fan, K, On systems of linear inequalities, (), 99-156, No. 38 · Zbl 0072.37602
[15] Fan, K, Convex sets and their applications, Argonne national laboratory lecture notes, (summer 1959), Argonne, Ill.
[16] Farkas, J, Uber die theorie der einfachen ungleichungen, J. reine angew. math., 124, 1-24, (1902) · JFM 32.0169.02
[17] Gale, D, Convex polyhedral cones and linear inequalities. chapt. 17, ()
[18] Gale, D, The theory of linear economic models, (1960), McGraw-Hill New York · Zbl 0114.12203
[19] Gerstenhaber, M, Theory of convex polyhedral cones, (), chapt. 18 · Zbl 0045.09708
[20] Goldman, A.J; Tucker, A.W, Polyhedral convex cones, (), 19-40, No. 38 · Zbl 0072.37504
[21] Goldstein, A.A, Constructive real analysis, (1967), Harper and Row New York · Zbl 0189.49703
[22] Good, R.A, Systems of linear relations, SIAM review, 1, 1-31, (1959) · Zbl 0231.15006
[23] Hanson, M.A; Mond, B, Quadratic programming in complex space, J. math. anal. appl., 20, 507-514, (1967) · Zbl 0157.50001
[24] Hoffman, A.J, Mathematical programming, () · Zbl 0407.05002
[25] Hoffman, A.J; McAndrew, M.S, Linear inequalities and analysis, () · Zbl 0178.35403
[26] Hurwicz, L, Programming in linear spaces, (), Chapt. 4 · Zbl 0133.12805
[27] ()
[28] Kuhn, H.W, Solvability and consistency for linear equations and inequalities, Amer. math. monthly, 63, 217-232, (1956) · Zbl 0070.25001
[29] ()
[30] Levinson, N, Linear programming in complex space, J. math. anal. appl., 14, 44-62, (1966) · Zbl 0136.13802
[31] Mirkil, H, New characterizations of polyhedral cones, Canad. J. math., 9, 1-4, (1957) · Zbl 0083.38302
[32] Motzkin, T.S; Motzkin, T.S; Motzkin, T.S, Beiträge zur theorie der linearen ungleichungen, Inaugural dissertation, Inaugural dissertation, U. S. air force, project rand, report T-22, (1952), English translation: · JFM 62.0054.01
[33] Nirenberg, L, Functional analysis, ()
[34] Pearl, M.H, A matrix proof of Farkas’s theorem, Quart. J. math. Oxford, 18, 193-197, (1967), (2) · Zbl 0259.15015
[35] Penrose, R, A generalized inverse for matrices, (), 406-413 · Zbl 0065.24603
[36] {\scA. W. Tucker}. Dual systems of homogeneous linear relations. In Ann. Math. Studies (H. W. Kuhn and A. W. Tucker, eds.), No. 38, pp. 3-18. Princeton Univ. Press, Princeton, New Jersey. · Zbl 0072.37503
[37] Uzawa, H, A theorem on convex polyhedral cones, (), chapt. 2 · Zbl 0989.91539
[38] Weyl, H, The elementary theory of convex polyhedra, (), 3-18 · Zbl 0041.25401
[39] Klee, V, Some characterizations of convex polyhedra, Acta Mathematica, 102, 79-107, (1959) · Zbl 0094.16802
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