let $l$ be a completely regular frame and $mathcal{r}l$ be the ring of continuous real-valued functions on $l$. we show that the lattice $zid(mathcal{r}l)$ of $z$-ideals of $mathcal{r}l$ is a normal coherent yosida frame, which extends the corresponding $c(x)$ result of mart'{i}nez and zenk. this we do by exhibiting $zid(mathcal{r}l)$ as a quotient of $rad(mathcal{r}l)$, the ...
