: ) wonderful world ( :

Encore une fois…

g:R^m→Rⁿ∧f:Rⁿ→R^k
“D(f)@g”∈R^m→R^{k x n}∧ D(g)∈R^m→R^{n x m}

It means that D(h) contains the partial differentials as columns and components as rows.

$ maple
    |\^/|     Maple 7 (IBM INTEL LINUX)
._|\|   |/|_. Copyright (c) 2001 by Waterloo Maple Inc.
 \  MAPLE  /  All rights reserved. Maple is a registered trademark of
 <____ ____>  Waterloo Maple Inc.
      |       Type ? for help.
> D(f@g);
                                ((D(f))@g) D(g)

> quit
bytes used=320280, alloc=327620, time=0.02
$