Effective Bounds from Ineffective Proofs in Analysis: An Application of Functional Interpretation and Majorization
Kohlenbach, Ulrich
J. Symbolic Logic, Tome 57 (1992) no. 1, p. 1239-1273 / Harvested from Project Euclid
We show how to extract effective bounds $\Phi$ for $\bigwedge u^1 \bigwedge v \leq_\gamma tu \bigvee w^\eta G_0$-sentences which depend on $u$ only (i.e. $\bigwedge u \bigwedge v \leq_\gamma tu \bigvee w \leq_\eta \Phi uG_0$) from arithmetical proofs which use analytical assumptions of the form \begin{equation*}\tag{*}\bigwedge x^\delta\bigvee y \leq_\rho sx \bigwedge z^\tau F_0\end{equation*} $(\gamma, \delta, \rho$, and $\tau$ are arbitrary finite types, $\eta \leq 2, G_0$ and $F_0$ are quantifier-free, and $s$ and $t$ are closed terms). If $\tau \leq 2, (\ast)$ can be weakened to $\bigwedge x^\delta, z^\tau\bigvee y \leq_\rho sx \bigwedge \tilde{z} \leq_\tau z F_0$. This is used to establish new conservation results about weak Konig's lemma. Applications to proofs in classical analysis, especially uniqueness proofs in approximation theory, will be given in subsequent papers.
Publié le : 1992-12-14
Classification: 
@article{1183744114,
     author = {Kohlenbach, Ulrich},
     title = {Effective Bounds from Ineffective Proofs in Analysis: An Application of Functional Interpretation and Majorization},
     journal = {J. Symbolic Logic},
     volume = {57},
     number = {1},
     year = {1992},
     pages = { 1239-1273},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1183744114}
}
Kohlenbach, Ulrich. Effective Bounds from Ineffective Proofs in Analysis: An Application of Functional Interpretation and Majorization. J. Symbolic Logic, Tome 57 (1992) no. 1, pp.  1239-1273. http://gdmltest.u-ga.fr/item/1183744114/