Let $L=\{\langle M_1 \rangle, \langle M_2 \rangle,...\}$ be a semi recursive language of gödel numbers of turing machines with input alphabet $\Sigma=\{0,1\}$ which always terminate and decide some language. Show that for every such $L$ there exists a recursive language $D$ (i.e. there is a turing machine that terminates and accepts iff input is in $D$) such that no turing machine $M_i$ with $\langle M_i \rangle$ in $L$ is a turing machine that decides $D$.
As a start I have enumerated the gödel numbers in $L$ and the words in $\Sigma^*$. I want to create an algorithm now which yields a desired language $D$
Any ideas ?