TY - JOUR A1 - Zheng, Xizhong T1 - Recursive approximability of real numbers KW - computable reals KW - semi-computable reals KW - weakly computable reals KW - recursively approximable realy Y1 - 2002 ER - TY - JOUR A1 - Zheng, Xizhong T1 - Closure properties on real numbers under limits and computable operators KW - weakly computable reals KW - computable real functions KW - closure properties Y1 - 2002 ER - TY - JOUR A1 - Rettinger, Robert A1 - Zheng, Xizhong A1 - Gengler, Romain A1 - Braunmühl, Burchard von T1 - Monotonically computable real numbers Y1 - 2002 ER -