皆様，

東北大学の横山です．

以下の日程でロジックセミナーを行いますので， ご興味のある方は是非ご参加ください．

日時：12月3日(金) 場所：東北大学北青葉山キャンパス理学総合棟1201号室 １５：３０〜 江口直日（JAIST） Title: Towards a Theory of Bounded Arithmetic for Polynomial Space Functions. Abstract: This talk presents an extension of familiar first order theories of bounded arithmetic. We would like to extend well-known characterizations of the polynomial time functions and the polynomial hierarchy by S. Buss to the polynomial space functions. We will define a class of functions via our new theory of bounded arithmetic and show that all the polynomial space functions are contained in this class. This work is still unfinished, but the speaker believes that the converse also holds, i.e., every function in the class defined by the new theory is computable in polynomial space.

セミナーの詳細につきましては， http://www.math.tohoku.ac.jp/~y-keita/friday-seminar/friday-seminar.html をご参照ください．

横山啓太 -- Keita Yokoyama Mathematical Institute, Tohoku University Aoba, Sendai, JAPAN, 980-8578 [email protected]

$B3'MM!$(B

$BElKLBg3X$N2#;3$G$9!%(B

$B0J2<$NF|Dx$G%m%8%C%/%;%_%J!<$r9T$$$^$9$N$G!$(B $B$46=L#$N$"$kJ}$O@'Hs$4;22C$/$@$5$$!%(B

$BF|;~!'(B12$B7n(B17$BF|(B($B6b(B) $B>l=j!'ElKLBg3XKL@DMU;3%-%c%s%Q%9M}3XAm9gEo(B1201$B9f<<(B $B#1#4!'#4#0!A#1#5!'#2#0(B $BHu8}9,<#{z!JElKLBg3XM}3X8&5f2J!K(B $B%?%$%H%k!'(BOn the degree structures of co-c.e. classes $B#1#5!'#3#0!A(B $B5FCS@?!J?@8MBg3X%7%9%F%`>pJs3X8&5f2J!K(B $B%?%$%H%k!'(BYablo $B$N5UM}$N7A<02=$HIT40A4@-DjM}(B

$B%;%_%J!<$N>:Y$K$D$-$^$7$F$O!$(B http://www.math.tohoku.ac.jp/~y-keita/friday-seminar/friday-seminar.html $B$r$4;2>H$/$@$5$$!%(B

$B2#;37<B@(B -- Keita Yokoyama Mathematical Institute, Tohoku University Aoba, Sendai, JAPAN, 980-8578 [email protected]