A Lift of a Theorem of Friedberg: A Banach-Mazur Functional that Coincides with No $\alpha$-Recursive Functional on the Class of $\alpha$-Recursive Functions
Paola, Robert A. Di
J. Symbolic Logic, Tome 46 (1981) no. 1, p. 216-232 / Harvested from Project Euclid
R. M. Friedberg demonstrated the existence of a recursive functional that agrees with no Banach-Mazur functional on the class of recursive functions. In this paper Friedberg's result is generalized to both $\alpha$-recursive functionals and weak $\alpha$-recursive functionals for all admissible ordinals $\alpha$ such that $\lambda < \alpha^\ast$, where $\alpha^\ast$ is the $\Sigma_1$-projectum of $\alpha$ and $\lambda$ is the $\Sigma_2$-cofinality of $\alpha$. The theorem is also established for the metarecursive case, $\alpha = \omega_1$, where $\alpha^\ast = \lambda = \omega$.
Publié le : 1981-06-14
Classification: 
@article{1183740770,
     author = {Paola, Robert A. Di},
     title = {A Lift of a Theorem of Friedberg: A Banach-Mazur Functional that Coincides with No $\alpha$-Recursive Functional on the Class of $\alpha$-Recursive Functions},
     journal = {J. Symbolic Logic},
     volume = {46},
     number = {1},
     year = {1981},
     pages = { 216-232},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1183740770}
}
Paola, Robert A. Di. A Lift of a Theorem of Friedberg: A Banach-Mazur Functional that Coincides with No $\alpha$-Recursive Functional on the Class of $\alpha$-Recursive Functions. J. Symbolic Logic, Tome 46 (1981) no. 1, pp.  216-232. http://gdmltest.u-ga.fr/item/1183740770/