"Creates a context modification, optionally initialized"
" via the list of modifications @var{mod-list}.")
{
- if (mod_list != SCM_UNDEFINED)
+ if (!SCM_UNBNDP (mod_list))
{
LY_ASSERT_TYPE (ly_cheap_is_list, mod_list, 1);
return Context_mod (mod_list).smobbed_copy ();