The indexof command returns the index of an item within the remaining sequence of arguments. The first item is in position 0, the second in position 1, and so on.

If k does not match any other item then -1 is returned.

$\mathrm{MapleTA}:-\mathrm{Builtin}:-\mathrm{indexof}\left(3\,2\,3\,5\,7\,11\right)$

$1$

$\mathrm{MapleTA}:-\mathrm{Builtin}:-\mathrm{indexof}\left(2\,2\,3\,5\,7\,11\right)$

$0$

$\mathrm{MapleTA}:-\mathrm{Builtin}:-\mathrm{indexof}\left(99\,2\,3\,5\,7\,11\right)$

$\mathrm{-1}$

The MapleTA[Builtin][indexof] command was introduced in Maple 18.

For more information on Maple 18 changes, see Updates in Maple 18.