  A function from sequences to their subsequences is called selection function.
A selection function is called admissible (with respect to normal numbers) if
for all normal numbers, their subsequences obtained by the selection function
are normal numbers.
  In Kamae (1973) selection functions that are not depend on sequences (depend
only on coordinates) are studied, and their necessary and sufficient condition
for admissibility is given. In this paper we introduce a notion of weak
randomness and study an algorithmic analogy to the Kamae's theorem.
