"@item\n"
"The vertical and horizontal extents of the object, given as"
" pairs. If an extent is unspecified (or if you use"
- " @code{(1000 . -1000)} as its value), it is taken to be empty.\n"
+ " @code{empty-interval} as its value), it is taken to be empty.\n"
"@end enumerate\n")
{
SCM_ASSERT_TYPE (!scm_is_pair (expr)