The index(p, rest) calling sequence is equivalent to constructing the expression p[rest].

If p is an indexable expression, index(p, rest) evaluates to the result of indexing p by rest; otherwise, it simply returns the indexed expression $p_{\mathrm{rest}}$.  For more about indexing, see selection.

Note: Calling index with one argument is equivalent to p[], that is, p indexed with an empty index.

$\mathrm{index}\left(f\,s\right)$

$f_s$

$\mathrm{index}\left(g\right)$

$g\left[\right]$

$\mathrm{index}\left(f\,s\,t\,u\,v\right)$

$f_{s,t,u,v}$

$\mathrm{index}\left(\left[7\,4\,8\,9\right]\,3\right)$

$8$

$\mathrm{map2}\left(\mathrm{index}\,\left[a\,b\,c\,d\right]\,\left[4\,2\,1\,3\right]\right)$

$\left[d\,b\,a\,c\right]$

The index command was introduced in Maple 2017.

For more information on Maple 2017 changes, see Updates in Maple 2017.