Resumen
Stationary memoryless sources produce two correlated random sequences ????
X
n
and ????
Y
n
. A guesser seeks to recover ????
X
n
in two stages, by first guessing ????
Y
n
and then ????
X
n
. The contributions of this work are twofold: (1) We characterize the least achievable exponential growth rate (in n) of any positive ??
?
-th moment of the total number of guesses when ????
Y
n
is obtained by applying a deterministic function f component-wise to ????
X
n
. We prove that, depending on f, the least exponential growth rate in the two-stage setup is lower than when guessing ????
X
n
directly. We further propose a simple Huffman code-based construction of a function f that is a viable candidate for the minimization of the least exponential growth rate in the two-stage guessing setup. (2) We characterize the least achievable exponential growth rate of the ??
?
-th moment of the total number of guesses required to recover ????
X
n
when Stage 1 need not end with a correct guess of ????
Y
n
and without assumptions on the stationary memoryless sources producing ????
X
n
and ????
Y
n
.