SIMPLEQ_FIRST
#define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
for((var) = SIMPLEQ_FIRST(head); \
for ((var) = SIMPLEQ_FIRST(head); \
for (ti = SIMPLEQ_FIRST(&$5.init_nodes);
for((var) = SIMPLEQ_FIRST(head); \