($\lambda$$r$,$p$,$q$,$E$,$z$. $\Sigma$($r$) $p$ $\leq$ $i$ $<$ $q$. $E$($i$)) $\in$ $r$:Rng$\rightarrow$$p$,$q$:$\mathbb{Z}\rightarrow$(\{$p$..$q$$^{-}$\}$\rightarrow\mid$$r$$\mid$)$\rightarrow$($\downarrow$True)$\rightarrow\mid$$r$$\mid$