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Portugaliae Mathematica

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Volume 77, Issue 3/4, 2020, pp. 399–408
DOI: 10.4171/PM/2056

Published online: 2020-12-22

Weak König’s lemma in herbrandized classical second-order arithmetic

Fernando Ferreira[1]

(1) Universidade de Lisboa, Portugal

This is a short paper describing how a herbrandized functional interpretation can give a new treatment of some issues in classical second-order arithmetic. It is perhaps worthy of note that, in our interpretation, second-order variables are interpreted by finite sets of natural numbers.

Keywords: Second-order arithmetic, herbrandized functional interpretation, weak König’s lemma

Ferreira Fernando: Weak König’s lemma in herbrandized classical second-order arithmetic. Port. Math. 77 (2020), 399-408. doi: 10.4171/PM/2056