“Priority method over intuitionistic logic”
Lunedì 25 Novembre 2024, ore 14:30 - Sala riunioni 7B1 - Takako Nemoto (Tohoku University, Sendai, Japan)
Abstract
In this talk, we consider how much non-constructive principles are sufficient for Friedberg-Muchinik construction of degree $d$ such that $0 \lt d \lt 0’$. We will see that the only point we need a non-constructive principle is to show “if a recursive set $S$ of natural number has finite cardinality, then $S$ has an upper bound”, which requires $\Sigma^0_1$ law of excluded middle.
