I think simple "map" does what you want:
 map(append,[[1,2],[3,4]],[[a,b],[c,d]]);
                =>  [[1,2,a,b],[3,4,c,d]]
On 9/12/06, Nicolas Neuss <neuss at mathematik.uni-karlsruhe.de> wrote:
> outermap(append,[[1,2],[3,4]],[[a,b],[c,d]]);
> I want to obtain [[1,2,a,b], ...