test_if1
defined (FALSE)
(if test 1)
defined (TRUE)
(if test 2)
defined (if test 3 level 1)
defined (if test 3 level 2)
defined (if test 3 level 3)
defined (if test 3 level 4 FALSE)
------------------
defined (TRUE)
(if test 1)
defined (FALSE)
(if test 2)
defined (if test 3 level 1)
defined (if test 3 level 2)
defined (if test 3 level 3)
defined (if test 3 level 4)