$p = 2$ in the global shape $s$ is $s' = s {\mathrel{\downarrow}}p = 5 - 2 = 3$ and a position $p' = 1$ in $s'$ is rendered as the position $p {\mathrel{\oplus}}p' = 2 + 1 = 3$ in the initial shape.

$$\xymatrix@C=5em@R=1.2em{
& & & & & \\
& & & & & \\
\bullet \ar@{->}@/_0.8pc/[rr]_(0.8){p = 2} \ar@{->}@/^0.8pc/[rrr]^{p {\mathrel{\oplus}}p' = 2 + 1 = 3} \ar@{-}[uurr]_>{s = 5} \ar@{-}[ddrr]  & \bullet & \bullet \ar@{.>}@/_0.8pc/[r]_>{p' = 1} \ar@{.}[uurr]_>{s' = s {\mathrel{\downarrow}}p = 5 - 2 = 3} \ar@{.}[ddrr] & \bullet & \bullet & \bullet \\
& & & & & \\
& & & & & 
}$$

Clearly one could also choose prefixes as subshapes and the last node of a non-empty list as the root, but this gives an isomorphic directed container.

Non-empty lists also give rise to an entirely different directed container structure that has *cyclic shifts* as “sublists” (this example was suggested to us by Jeremy Gibbons). The subshape at each position is the global shape ($s {\mathrel{\downarrow}}p = s$). The root is still ${\mathsf{o}}\, {\{s\}} = 0$. The interesting part is that translation into the global shape of a subshape position is defined 