Consider two distributions p$($x$)$ and q$($x$)$ on the same alphabet

X $.$ We want to design a source code that works with either distribution. For any $>0,$ find a fixedto$-$fixed source code with probability of error less than $$ if the underlying distribution is either p$($x$)$ or

q$($x$),$ and where the number of compressed bits satisfies

k $<=$ n$($max$\{$Hp$($X$),$ Hq$($X$)\}+)$

where Hp and Hq refer to the entropies under p$($x$)$ and q$($x$)$ respectively