Schmidhuber's 2014 survey names Werbos's 1981 DOE gas-market application — not the pre-1974 Deutsch project — as 'the first NN-specific application of efficient BP'

paul-werbosjurgen-schmidhuberbackpropagationhistory-of-mlpriority-vs-paternitywhat-was-firstnatural-gas-market-model

Jürgen Schmidhuber's "Deep Learning in Neural Networks: An Overview" (arXiv:1404.7828v4) states its own "first" for backpropagation's application to neural networks: "To my knowledge, the first NN-specific application of efficient BP as above was described in 1981 (Werbos, 1981, 2006). Related work was published several years later (Parker, 1985; LeCun, 1985, 1988)." What the survey itself names is the reference — Werbos (1981), "Applications of advances in nonlinear sensitivity analysis," Proceedings of the 10th IFIP Conference, pp. 762–770, with Werbos's 2006 retrospective AD chapter alongside — not the application's domain: the word "gas" appears nowhere in the survey's text outside the Werbos (1988) reference title. Identifying that 1981 application as Werbos's own DOE-developed natural-gas-market model is a bridge supplied by Werbos's own 1988 paper, which states "This generalization was applied in 1981 to a model of natural gas markets" (claim-werbos-1988-doe-affiliation-and-gas-market-test-case, Tier 1, verified verbatim). Either way, the application Schmidhuber dates to 1981 is not the pre-1974 Karl Deutsch nationalism-forecasting project that Werbos's own 1988 paper separately names "the first actual application of backpropagation" (see claim-werbos-1988-credits-deutsch-project-as-first-actual-application-of-backpropagation).

This adds a fifth candidate to the vault's running list of "what was first" for backpropagation, alongside the Deutsch project (first actual application, per Werbos's own 1988 account), the 1974 dissertation (first documented), the 1975 TSP manual (first published command), and the 1968 Cybernetica paper (earliest germ). Unlike the other four, this fifth entry is not Werbos's own characterization of his career — it is an external historian's framing of one specific 1981 application, made 33 years later, in a survey that elsewhere never engages Werbos's own "first actual application" claim at all (see observation-lecun-1989-werbos-1988-deutsch-cosine-0881-pairing-is-analytical-contrast).