[m-rev.] diff: improve list.m

[Julien Fischer]

Hi Zoltan,

On Tue, 18 Aug 2015, Zoltan Somogyi wrote:

> The diff itself is uninteresting, but it does raise a question. Since
> nth_member_search is identical to index1_of_first_occurrence,
> and nth_member_lookup is identical to det_index1_of_...,
> should we mark the former as obsolete?

I'm going to say yes, since there's no particularly compelling reason to
keep both.

Cheers,
Julien.