Lecture Notes in Economics and Mathematical Systems

Economic Models, Estimation and Risk Programming: Essays in Honor of Gerhard Tintner: Essays in Honor of Gerhard Tintner

Lecture Notes in Economics and Mathematical Systems, nr. 15

Editat de K. A. Fox et al.

1969

Preț: 629^.48 lei 740^.57 lei

6-8 săpt.

-15%

Berechnung optimaler Steuerungen: Maximumprinzip und dynamische Optimierung

Lecture Notes in Economics and Mathematical Systems, nr. 17

Autor H. Bauer et al.

1969

Preț: 403^.10 lei

6-8 săpt.

Graphentheorie in Planungs- und Tourenproblemen: am Beispiel des städtischen Straßendienstes

Lecture Notes in Economics and Mathematical Systems, nr. 21

Autor Thomas M. Liebling

Preț: 398^.66 lei

6-8 săpt.

Sensitivitätsanalyse bei diskreten linearen Optimierungsproblemen

Lecture Notes in Economics and Mathematical Systems, nr. 30

Autor H. Noltemeier

Preț: 396^.99 lei

6-8 săpt.

Homomorphismen und Reduktionen linearer Sprachen

Lecture Notes in Economics and Mathematical Systems, nr. 32

Autor F. Bartholomes et al.

Preț: 400^.49 lei

6-8 săpt.

Foundations of Non-stationary Dynamic Programming with Discrete Time Parameter

Lecture Notes in Economics and Mathematical Systems, nr. 33

Autor K. Hinderer

Preț: 368^.96 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 58

Autor Paul B. Hagelschuer

1971

Preț: 403^.10 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 59

Autor J. A. Hanson

1971

Preț: 366^.76 lei

6-8 săpt.

Monte Carlo Simulation im Operations Research

Lecture Notes in Economics and Mathematical Systems, nr. 63

Autor Juerg Kohlas

4 feb 1972

Preț: 401^.27 lei

6-8 săpt.

A Theory of Supercritical Wing Sections, with Computer Programs and Examples: With Computer Programs and Examples

Lecture Notes in Economics and Mathematical Systems, nr. 66

Autor F. Bauer et al.

21 apr 1972

Preț: 697^.67 lei 850^.82 lei

6-8 săpt.

-18%

The Economic Effects of Floods: Investigations of a Stochastic Model of Rational Investment Behavior in the Face of Floods

Lecture Notes in Economics and Mathematical Systems, nr. 70

Autor J. P. Brown

24 iul 1972

Preț: 363^.78 lei

6-8 săpt.

Numerical Methods in Markov Chains and Bulk Queues

Lecture Notes in Economics and Mathematical Systems, nr. 72

Autor T. P. Bagchi et al.

29 sep 1972

Preț: 364^.56 lei

6-8 săpt.

1. Fachtagung über Programmiersprachen: München, 9.–11. März 1971

Lecture Notes in Economics and Mathematical Systems, nr. 75

Editat de Hans Langmaack et al.

30 oct 1972

Preț: 350^.57 lei 438^.22 lei

6-8 săpt.

-20%

Optimale Entscheidung bei mehrfacher Zielsetzung

Lecture Notes in Economics and Mathematical Systems, nr. 76

Autor G. Fandel

11 dec 1972

Preț: 397^.92 lei

6-8 săpt.

Cones, Matrices and Mathematical Programming

Lecture Notes in Economics and Mathematical Systems, nr. 79

Autor Abraham Berman

5 feb 1973

Preț: 364^.56 lei

6-8 săpt.

NTG/GI Gesellschaft für Informatik Nachrichtentechnische Gesellschaft. Fachtagung „Cognitive Verfahren und Systeme“: Hamburg, 11.–13. April 1973

Lecture Notes in Economics and Mathematical Systems, nr. 83

Editat de Theodor Einsele et al.

19 apr 1973

Preț: 355^.95 lei 444^.94 lei

6-8 săpt.

-20%

Stochastic Differential Systems I: Filtering and Control A Function Space Approach

Lecture Notes in Economics and Mathematical Systems, nr. 84

Autor A. V. Balakrishnan

30 apr 1973

Preț: 622^.12 lei 777^.65 lei

6-8 săpt.

-20%

Posterior and Predictive Densities for Simultaneous Equation Models

Lecture Notes in Economics and Mathematical Systems, nr. 90

Autor J.-F. Richard

30 noi 1973

Preț: 371^.93 lei

6-8 săpt.

General Equilibrium with Price-Making Firms

Lecture Notes in Economics and Mathematical Systems, nr. 91

Autor T. Marschak et al.

15 feb 1974

Preț: 373^.40 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 100

Autor B. S. Duran et al.

10 oct 1974

Preț: 366^.40 lei

3-5 săpt.

Optimal Subset Selection: Multiple Regression, Interdependence and Optimal Network Algorithms

Lecture Notes in Economics and Mathematical Systems, nr. 103

Autor David Boyce et al.

24 oct 1974

Preț: 370^.26 lei

6-8 săpt.

Resource Allocation and Division of Space: Proceedings of an International Symposium Held at Toba Near Nagoya, Japan 14–17 December, 1975

Lecture Notes in Economics and Mathematical Systems, nr. 147

Editat de T. Fujii et al.

sep 1977

Preț: 612^.55 lei 720^.65 lei

6-8 săpt.

-15%

Stationäre und schrumpfende Bevölkerungen: Demographisches Null- und Negativwachstum in Österreich

Lecture Notes in Economics and Mathematical Systems, nr. 149

Editat de Gustav Feichtinger

aug 1977

Preț: 470^.24 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 150

Autor F. Bauer et al.

dec 1977

Preț: 369^.16 lei

6-8 săpt.

Notwendige Optimalitätsbedingungen und ihre Anwendung

Lecture Notes in Economics and Mathematical Systems, nr. 152

Autor A. Kirsch et al.

1978

Preț: 398^.30 lei

6-8 săpt.

Kombinatorische Entscheidungsprobleme: Methoden und Anwendungen: Fortbildungskurs des Instituts für Operations Research der ETH Zürich

Lecture Notes in Economics and Mathematical Systems, nr. 153

Editat de T. M. Liebling et al.

1978

Preț: 402^.90 lei

6-8 săpt.

Multiple Criteria Problem Solving: Proceedings of a Conference Buffalo, N.Y. (U.S.A), August 22 – 26, 1977

Lecture Notes in Economics and Mathematical Systems, nr. 155

Editat de S. Zionts

feb 1978

Preț: 632^.96 lei 744^.65 lei

6-8 săpt.

-15%

Lecture Notes in Economics and Mathematical Systems, nr. 161

Autor Martin F. Bach

5 oct 1978

Preț: 368^.43 lei

6-8 săpt.

Optimale Entscheidungen in Organisationen

Lecture Notes in Economics and Mathematical Systems, nr. 163

Autor G. Fandel

5 ian 1979

Preț: 430^.76 lei

6-8 săpt.

Multiple Objective Decision Making — Methods and Applications: A State-of-the-Art Survey

Lecture Notes in Economics and Mathematical Systems, nr. 164

S.R. Paidy et al.

5 feb 1979

Preț: 380^.46 lei

6-8 săpt.

Introduction to Modern Austrian Capital Theory

Lecture Notes in Economics and Mathematical Systems, nr. 167

Autor Malte Faber

5 mar 1979

Preț: 370^.46 lei

6-8 săpt.

Extremal Methods and Systems Analysis: An International Symposium on the Occasion of Professor Abraham Charnes’ Sixtieth Birthday Austin, Texas, September 13 – 15, 1977

Lecture Notes in Economics and Mathematical Systems, nr. 174

Editat de A. V. Fiacco et al.

1980

Preț: 632^.02 lei 743^.56 lei

6-8 săpt.

-15%

Optimization with Disjunctive Constraints

Lecture Notes in Economics and Mathematical Systems, nr. 181

Autor H. D. Sherali et al.

aug 1980

Preț: 367^.85 lei

6-8 săpt.

Barriers to Entry: A Theoretical Treatment

Lecture Notes in Economics and Mathematical Systems, nr. 185

Autor C. C. v. Weizsäcker

noi 1980

Preț: 371^.73 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 188

Autor D. Bös

apr 1981

Preț: 366^.95 lei

6-8 săpt.

Organizations: Multiple Agents with Multiple Criteria: Proceedings of the Fourth International Conference on Multiple Criteria Decision Making, University of Delaware, Newark, August 10–15, 1980

Lecture Notes in Economics and Mathematical Systems, nr. 190

Editat de J. N. Morse

mai 1981

Preț: 629^.85 lei 740^.99 lei

6-8 săpt.

-15%

Robust Methods and Asymptotic Theory in Nonlinear Econometrics

Lecture Notes in Economics and Mathematical Systems, nr. 192

Autor H. J. Bierens

iun 1981

Preț: 370^.62 lei

6-8 săpt.

Die elementare Katastrophentheorie: Eine Darstellung aus der Sicht der Ökonomie

Lecture Notes in Economics and Mathematical Systems, nr. 195

Autor H. W. Ursprung

dec 1981

Preț: 474^.66 lei

6-8 săpt.

Information Structures in Economics: Studies in the Theory of Markets with Imperfect Information

Lecture Notes in Economics and Mathematical Systems, nr. 196

Autor M. Nermuth

1982

Preț: 373^.03 lei

6-8 săpt.

Ein ökonomisches Modell des Arztverhaltens

Lecture Notes in Economics and Mathematical Systems, nr. 198

Autor P. Zweifel et al.

apr 1982

Preț: 479^.31 lei

6-8 săpt.

Compilation of Input-Output Tables: Proceedings of a Session of the 17th General Conference of the International Association for Research in Income and Wealth, Gouvieux, France, August 16 – 22, 1981

Lecture Notes in Economics and Mathematical Systems, nr. 203

Editat de J. V. Skolka et al.

sep 1982

Preț: 618^.99 lei 728^.23 lei

6-8 săpt.

-15%

Redundancy in Mathematical Programming: A State-of-the-Art Survey

Lecture Notes in Economics and Mathematical Systems, nr. 206

Autor M. H. Karwan et al.

apr 1983

Preț: 617^.89 lei 726^.93 lei

6-8 săpt.

-15%

Econometric Decision Models: Proceedings of a Conference Held at the University of Hagen, West Germany, June 19–20, 1981

Lecture Notes in Economics and Mathematical Systems, nr. 208

Editat de J. Gruber

mai 1983

Preț: 619^.45 lei 728^.76 lei

6-8 săpt.

-15%

Essays and Surveys on Multiple Criteria Decision Making: Proceedings of the Fifth International Conference on Multiple Criteria Decision Making, Mons, Belgium, August 9–13, 1982

Lecture Notes in Economics and Mathematical Systems, nr. 209

Editat de P. Hansen

feb 1983

Preț: 623^.22 lei 733^.20 lei

6-8 săpt.

-15%

Technology, Organization and Economic Structure: Essays in Honor of Prof. Isamu Yamada

Lecture Notes in Economics and Mathematical Systems, nr. 210

Editat de R. Sato et al.

mar 1983

Preț: 611^.74 lei 719^.70 lei

6-8 săpt.

-15%

The Stability of a Macroeconomic System with Quantity Constraints

Lecture Notes in Economics and Mathematical Systems, nr. 211

Autor P. van den Heuvel

feb 1983

Preț: 368^.79 lei

6-8 săpt.

Invariance Principles and the Structure of Technology

Lecture Notes in Economics and Mathematical Systems, nr. 212

Autor R. Sato et al.

mar 1983

Preț: 363^.99 lei

6-8 săpt.

An Inter-Industry Translog Model of Prices and Technical Change for the West German Economy

Lecture Notes in Economics and Mathematical Systems, nr. 221

Autor S. Nakamura

dec 1983

Preț: 376^.75 lei

6-8 săpt.

Energy Systems Analysis for Developing Countries

Lecture Notes in Economics and Mathematical Systems, nr. 222

Autor P. Meier

1984

Preț: 379^.51 lei

6-8 săpt.

Selected Topics in Operations Research and Mathematical Economics: Proceedings of the 8th Symposium on Operations Research, Held at the University of Karlsruhe, West Germany August 22–25, 1983

Lecture Notes in Economics and Mathematical Systems, nr. 226

Editat de G. Hammer et al.

apr 1984

Preț: 628^.24 lei 739^.10 lei

6-8 săpt.

-15%

Risk and Capital: Proceedings of the 2nd Summer Workshop on Risk and Capital Held at the University of Ulm, West Germany June 20–24,1983

Lecture Notes in Economics and Mathematical Systems, nr. 227

Editat de G. Bamberg et al.

apr 1984

Preț: 618^.99 lei 728^.23 lei

6-8 săpt.

-15%

Bayesian Full Information Analysis of Simultaneous Equation Models Using Integration by Monte Carlo

Lecture Notes in Economics and Mathematical Systems, nr. 232

Autor L. Bauwens

sep 1984

Preț: 365^.29 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 318

Autor Timothy M. Doup

14 sep 1988

Preț: 372^.31 lei

6-8 săpt.

Financial Structure in Small Business: Theory, Tests and Applications

Lecture Notes in Economics and Mathematical Systems, nr. 320

Autor Dominicus van der Wijst

7 dec 1988

Preț: 369^.53 lei

6-8 săpt.

Technological and Social Factors in Long Term Fluctuations: Proceedings of an International Workshop Held in Siena, Italy, December 16–18, 1986

Lecture Notes in Economics and Mathematical Systems, nr. 321

Editat de Massimo Di Matteo et al.

21 dec 1988

Preț: 626^.36 lei 736^.90 lei

6-8 săpt.

-15%

Game Theoretical Foundations of Evolutionary Stability

Lecture Notes in Economics and Mathematical Systems, nr. 324

Autor Immanuel M. Bomze et al.

22 feb 1989

Preț: 367^.12 lei

6-8 săpt.

Optimal Dynamic Investment Policies of a Value Maximizing Firm

Lecture Notes in Economics and Mathematical Systems, nr. 330

Autor Peter M. Kort

10 mai 1989

Preț: 369^.74 lei

6-8 săpt.

Cost Analysis Applications of Economics and Operations Research: Proceedings of the Institute of Cost Analysis National Conference, Washington, D.C., July 5–7, 1989

Lecture Notes in Economics and Mathematical Systems, nr. 332

Stephen J. Balut et al.

10 iul 1989

Preț: 384^.68 lei

6-8 săpt.

Stochastic Project Networks: Temporal Analysis, Scheduling and Cost Minimization

Lecture Notes in Economics and Mathematical Systems, nr. 344

Autor Klaus Neumann

10 iul 1990

Preț: 371^.37 lei

6-8 săpt.

Generalized Convexity and Fractional Programming with Economic Applications: Proceedings of the International Workshop on “Generalized Concavity, Fractional Programming and Economic Applications” Held at the University of Pisa, Italy, May 30 – June 1, 1988

Lecture Notes in Economics and Mathematical Systems, nr. 345

Editat de Alberto Cambini et al.

10 iul 1990

Preț: 619^.45 lei 728^.76 lei

6-8 săpt.

-15%

Dynamic Modelling of Stochastic Demand for Manufacturing Employment

Lecture Notes in Economics and Mathematical Systems, nr. 349

Autor Gerard A. Pfann

12 sep 1990

Preț: 367^.85 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 357

Autor Peter Zörnig

13 noi 1991

Preț: 370^.62 lei

6-8 săpt.

Essays in Macroeconomics of an Open Economy

Lecture Notes in Economics and Mathematical Systems, nr. 362

Autor Franz Gehrels

19 iun 1991

Preț: 369^.90 lei

6-8 săpt.

Distorted Probabilities and Choice under Risk

Lecture Notes in Economics and Mathematical Systems, nr. 363

Autor Clemens Puppe

10 iul 1991

Preț: 363^.41 lei

6-8 săpt.

Are Policy Variables Exogenous?: The Econometric Implications of Learning while Maximizing

Lecture Notes in Economics and Mathematical Systems, nr. 364

Autor Balazs Horvath

28 aug 1991

Preț: 366^.95 lei

6-8 săpt.

Balanced Silverman Games on General Discrete Sets

Lecture Notes in Economics and Mathematical Systems, nr. 365

Autor Gerald A. Heuer et al.

11 sep 1991

Preț: 366^.76 lei

6-8 săpt.

Parallel Computing and Mathematical Optimization: Proceedings of the Workshop on Parallel Algorithms and Transputers for Optimization, Held at the University of Siegen, FRG, November 9, 1990

Lecture Notes in Economics and Mathematical Systems, nr. 367

Editat de Manfred Grauer et al.

9 oct 1991

Preț: 618^.46 lei 773^.07 lei

6-8 săpt.

-20%

The Visible Hand: Synergetic Microfoundation of Macroeconomic Dynamics

Lecture Notes in Economics and Mathematical Systems, nr. 369

Autor Reiner B. Koblo

13 noi 1991

Preț: 365^.09 lei

6-8 săpt.

The Social Viability of Money: Competitive Equilibria and the Core of Overlapping Generations Economies

Lecture Notes in Economics and Mathematical Systems, nr. 372

Autor Joan Esteban

11 dec 1991

Preț: 371^.00 lei

6-8 săpt.

Fuzzy Multiple Attribute Decision Making: Methods and Applications

Lecture Notes in Economics and Mathematical Systems, nr. 375

F.P. Hwang et al.

15 ian 1992

Preț: 631^.53 lei 742^.98 lei

6-8 săpt.

-15%

Stochastic Optimization: Numerical Methods and Technical Applications

Lecture Notes in Economics and Mathematical Systems, nr. 379

Editat de Kurt Marti

8 apr 1992

Preț: 369^.53 lei

6-8 săpt.

The Monetary Model of Exchange Rates and Cointegration: Estimation, Testing and Prediction

Lecture Notes in Economics and Mathematical Systems, nr. 385

Autor Javier Gardeazabal et al.

5 aug 1992

Preț: 370^.46 lei

6-8 săpt.

Experimental Duopoly Markets with Demand Inertia: Game-Playing Experiments and the Strategy Method

Lecture Notes in Economics and Mathematical Systems, nr. 391

Autor Claudia Keser

17 dec 1992

Preț: 367^.70 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 392

Autor Karl Frauendorfer

17 dec 1992

Preț: 372^.67 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 398

Autor Jean-Pierre Urbain

14 iun 1993

Preț: 370^.62 lei

6-8 săpt.

Generalized Convexity: Proceedings of the IVth International Workshop on Generalized Convexity Held at Janus Pannonius University Pécs, Hungary, August 31–September 2, 1992

Lecture Notes in Economics and Mathematical Systems, nr. 405

Editat de Sandor Komlosi et al.

28 mar 1994

Preț: 621^.67 lei 731^.37 lei

6-8 săpt.

-15%

Empirical Vector Autoregressive Modeling

Lecture Notes in Economics and Mathematical Systems, nr. 407

Autor Marius Ooms

28 mar 1994

Preț: 620^.68 lei 730^.21 lei

6-8 săpt.

-15%

An Integrated Approach in Production Planning and Scheduling

Lecture Notes in Economics and Mathematical Systems, nr. 411

Autor Stephane Dauzere-Peres et al.

27 mai 1994

Preț: 366^.19 lei

6-8 săpt.

Two-Person Bargaining Experiments with Incomplete Information

Lecture Notes in Economics and Mathematical Systems, nr. 412

Autor Bettina Kuon

28 iun 1994

Preț: 374^.34 lei

6-8 săpt.

Imperfect General Equilibrium: The Economy as an Evolutionary Process: Individualistic, Discrete, Deterministic

Lecture Notes in Economics and Mathematical Systems, nr. 415

Autor Pier C. Nicola

29 aug 1994

Preț: 367^.49 lei

6-8 săpt.

Nonlinear and Convex Analysis in Economic Theory

Lecture Notes in Economics and Mathematical Systems, nr. 419

Editat de Toru Maruyama et al.

17 feb 1995

Preț: 620^.55 lei 730^.06 lei

6-8 săpt.

-15%

Nonlinear Dynamics in Economics: A Theoretical and Statistical Approach to Agricultural Markets

Lecture Notes in Economics and Mathematical Systems, nr. 426

Autor Bärbel Finkenstädt

14 iul 1995

Preț: 609^.85 lei 717^.46 lei

6-8 săpt.

-15%

Causal and Stochastic Elements in Business Cycles: An Essential Extension of Macroeconomics Leading to Improved Predictions of Data

Lecture Notes in Economics and Mathematical Systems, nr. 431

Autor Arvid Aulin

19 feb 1996

Preț: 364^.56 lei

6-8 săpt.

Interest Rate Dynamics, Derivatives Pricing, and Risk Management

Lecture Notes in Economics and Mathematical Systems, nr. 435

Autor Lin Chen

7 mar 1996

Preț: 366^.40 lei

6-8 săpt.

Batching and Scheduling: Models and Methods for Several Problem Classes

Lecture Notes in Economics and Mathematical Systems, nr. 437

Autor Carsten Jordan

18 iun 1996

Preț: 367^.85 lei

6-8 săpt.

Litigation and Settlement in a Game with Incomplete Information: An Experimental Study

Lecture Notes in Economics and Mathematical Systems, nr. 440

Autor Wolfgang Ryll

12 iul 1996

Preț: 367^.70 lei

6-8 săpt.

Dynamic Competitive Analysis in Marketing: Proceedings of the International Workshop on Dynamic Competitive Analysis in Marketing, Montréal, Canada, September 1–2, 1995

Lecture Notes in Economics and Mathematical Systems, nr. 444

Editat de Steffen Jorgensen et al.

18 noi 1996

Preț: 615^.66 lei 724^.31 lei

6-8 săpt.

-15%

Encompassing: Formulation, Properties and Testing

Lecture Notes in Economics and Mathematical Systems, nr. 446

Autor Geert Dhaene

28 ian 1997

Preț: 367^.12 lei

6-8 săpt.

Multiple Criteria Decision Making: Proceedings of the Twelfth International Conference Hagen (Germany)

Lecture Notes in Economics and Mathematical Systems, nr. 448

T. Hanne et al.

20 feb 1997

Preț: 634^.38 lei 746^.32 lei

3-5 săpt.

-15%

Stochastic Programming Methods and Technical Applications: Proceedings of the 3rd GAMM/IFIP-Workshop on “Stochastic Optimization: Numerical Methods and Technical Applications” held at the Federal Armed Forces University Munich, Neubiberg/München, Germany, June 17–20, 1996

Lecture Notes in Economics and Mathematical Systems, nr. 458

Editat de Kurt Marti et al.

18 mar 1998

Preț: 381^.72 lei

6-8 săpt.

Lecture Notes in Economics and Mathematical Systems, nr. 460

Editat de Bernhard Fleischmann et al.

20 mai 1998

Preț: 918^.47 lei 1120^.08 lei

6-8 săpt.

-18%

The Impact of Science on Economic Growth and its Cycles: The Mathematical Dynamics Determined by the Basic Macroeconomic Facts

Lecture Notes in Economics and Mathematical Systems, nr. 464

Autor Arvid Aulin

17 sep 1998

Preț: 369^.16 lei

6-8 săpt.

The Alternating Double Auction Market: A Game Theoretic and Experimental Investigation

Lecture Notes in Economics and Mathematical Systems, nr. 466

Autor Abdolkarim Sadrieh

28 oct 1998

Preț: 618^.83 lei 728^.03 lei

6-8 săpt.

-15%

Performance Analysis of Flow Lines with Non-Linear Flow of Material

Lecture Notes in Economics and Mathematical Systems, nr. 473

Autor Stefan Helber

19 aug 1999

Preț: 373^.24 lei

6-8 săpt.

Equity, Efficiency and Evolutionary Stability in Bargaining Games with Joint Production

Lecture Notes in Economics and Mathematical Systems, nr. 483

Autor Manfred Königstein

6 mar 2000

Preț: 368^.96 lei

6-8 săpt.

Equilibrium Models in an Applied Framework: Industrial Structure and Transformation

Lecture Notes in Economics and Mathematical Systems, nr. 667

Autor Ronny Norén

8 mar 2013

Preț: 365^.65 lei

6-8 săpt.

Papetărie, jocuri, reviste

Lecture Notes in Economics and Mathematical Systems