Gerard Debreu (1954), “Representation of a preference ordering by a numerical function”, in R. M. Thrall, C. H. Coombs & R. L. Davis (eds), Decision Processes, Wiley, pp. 159–165. Reprinted in G. Debreu, Mathematical Economics (Cambridge University Press, 1983), ch. 6 — DOI-10.1017/CCOL052123736X.007

Key takeaways

Registered, not read. What is said here comes from Debreu’s restatement in Theory of Value (LIT-1435), not from this paper.

  • The theorem as Debreu later credits it to this paper. On a space satisfying the second axiom of countability, a continuous complete preorder has a continuous utility function, and connectedness is not needed. Theory of Value, p. 73: “the assumption of connectedness has been removed for spaces satisfying the second axiom of countability in G. Debreu [3]”.
  • The lexicographic counterexample. Theory of Value gives the lexicographic ordering of R² as a complete preordering with no real-valued representation (p. 72). Whether this paper also gives it is not known here.

Standing in the record

Filed on 2026-10-23 because CLAIM-436 rests its third part on “Debreu’s representation theorem”. That part states the theorem for “a connected, separable topological space”. In Theory of Value Debreu credits that form to Eilenberg (“essentially a result of S. Eilenberg”), and keeps this paper for the second-countable form without connectedness. The claim’s statement is correct, but the attribution should be “Eilenberg (1941); Debreu (1954)”, or the claim should use the second-countable form if it means to cite this paper. See NOTE-1112.

No instruction for machine-learning practice; nothing here belongs in the anthology.