Saddle Point
Back to the cover

Part I · Foundations

  1. 0 Mathematical Foundations
  2. 1 Observation, Beliefs, and Decision

Part II · Engines

  1. 2 Competing for Allocation: The Blotto Game
  2. 3 Bargaining, Commitment, and Repeated Cooperation
  3. 4 Signals, Disclosure, and Persuasion
  4. 5 Different Models of One Game
  5. 6 Leadership and Rules: Inspection
  6. 7 Decisions in Time
  7. 8 Many Agents
  8. 9 Networks, Dependence, and Resilience
  9. 10 Aggregating Information

Part III · Systems

  1. 11 Architecture of Decision Support
  2. 12 Simulation and Wargaming with AI Agents

Part IV · Limits

  1. 13 Where the Mathematics Stops

Chapter 9 · Networks, Dependence, and Resilience

Lester R. Ford Jr.

1927 – 2017

The problem on the desk

Harris’s railway-capacity question led Ford and Fulkerson to ask for the largest feasible flow between two cities. Their theorem relates that maximum to the capacity of a separating cut.1

A life in moments

  1. 1927

    Houston

    Born on 23 September.2

  2. 1949

    University of Chicago · Chicago

    Completed his bachelor’s degree.2

  3. 1950

    University of Chicago · Chicago

    Completed his master’s degree.2

  4. 1953

    University of Illinois · Urbana

    Completed his doctorate.2

  5. 1956

    RAND Corporation · Santa Monica

    Co-authored Maximal Flow Through a Network.3

  6. 2017

    Died on 26 February.2

Every line rests on a dated source (numbered below) unless it carries a mark: R for an inference, S for a story as told.

In their own words

The proof is non-constructive.

Maximal Flow Through a Network, 19563

A story

A theorem before a general algorithm

The 1956 paper explicitly calls its theorem proof non-constructive, then gives a procedure for a planar case. The paper should not be described as the modern general augmenting-path presentation.4

Around Ford

  • co-author D. Ray Fulkerson Ford and Fulkerson jointly authored the 1956 network-flow paper.3

Recorded as advisor David Gordon Bourgin Mathematics Genealogy Project record

The genealogy lists only what the database records; a missing name is not a missing teacher.

The card in the book

Mathematician who worked at the RAND Corporation in the 1950s. With D. R. Fulkerson he proved the max-flow min-cut theorem and gave the augmenting-path algorithm for maximum flows; his name is also attached to the Bellman–Ford shortest-path algorithm and, with S. M. Johnson, to the Ford–Johnson merge-insertion sorting method.

Main works “Maximal flow through a network”, with D. R. Fulkerson (Canadian J. Math. 8, 1956); Flows in Networks, with D. R. Fulkerson (1962).

To read further

Sources (4)
  1. Maximal Flow Through a Network, L. R. Ford Jr. and D. R. Fulkerson, 1956; pp. 399–400
  2. Lester R. Ford Jr. of Santa Barbara, 1927–2017, Ilisa Kim, 2017; Obituary by his daughter; education, employment and personal recollections
  3. Maximal Flow Through a Network, L. R. Ford Jr. and D. R. Fulkerson, 1956; p. 399
  4. Maximal Flow Through a Network, L. R. Ford Jr. and D. R. Fulkerson, 1956; p. 399 and §2

The facts on this page were gathered for the site from the sources listed, each checked against its locator; the book's card is reproduced unchanged.