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arXiv · 1302.1488

On Maximum Conservative Extensions

Henry Towsner
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Abstract

We investigate the set of Pi-1-2 sentences which are Pi-1-1 conservative over the theories of reverse mathematics RCA0+ISigma_n and ACA0. We exhibit new elements of these sets and conclude that the sets are Pi_2 complete. Along the way, we show that, over the theory RCA, induction for Sigma-n formulas has essentially no consequences for Delta-(n+1) formulas.

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Henry Towsner. 2013-08-23. On Maximum Conservative Extensions. https://arxiv.org/abs/1302.1488

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