On 29/08/2011 09:43, Ulrike Fischer wrote: > Assuming that I have a token list variable like this: > > \tl_set:Nn \l_temp_tl { a b c {e f} g {h} i }. > > What is the right way to remove the inner braces and convert it to > > { a b c e f g h i } > > ? (spaces don't matter) > > (I want to loop through the list, but I need simply chars as > arguments) The is no pre-build 'strip_braces' function at present. You don't say if we are talking one set of braces or multiple sets. For the former case, a simple 'do nothing' loops would be easiest: \RequirePackage{expl3} \ExplSyntaxOn \tl_new:N \l_temp_tl \tl_set:Nn \l_temp_tl { a b c {e f} g {h} i } \tl_set:Nx \l_temp_tl { \tl_map_function:NN \l_temp_tl \exp_not:n } \tl_show:N \l_temp_tl -- Joseph Wright