Begin First a Second (no delay) a b Nest begin a b c After nest begin Nest second a b c d Test par par2 0 after 0 par2 1 after 0.02 par2 2 after 0.04 par2 3 after 0.06 par2 4 after 0.08 par1 4 after 0.42 par1 3 after 0.44 par1 2 after 0.46 par1 1 after 0.48 nex 2 after 0.49 par1 0 after 0.5 nex 1 after 0.52 nex 0 after 0.55 Done a b c 0 1 2 0 1 2 3 4 4 3 2 1 0 Jobs begin Job 1 begin Job 2 begin Jobs begun next should be invoked only once at demo_all.pl line 99. Job 2 done Job 1 done Jobs done Cir1 1 begin One shot! Cir2 1 begin Cir1 1 second Cir1 1 repeat Cir1 2 begin Cir2 1 second Cir1 2 second Cir1 2 repeat Cir1 3 begin Cir2 1 repeat Cir2 2 begin Cir1 3 second Cir1 3 repeat Cir1 4 begin Cir1 4 second Cir2 2 second Cir1 4 repeat Cir1 5 begin Cir1 5 second Cir2 2 repeat Cir2 3 begin Cir1 5 repeat Cir1 6 begin Cir1 6 second Cir1 6 repeat Cir1 7 begin Cir2 3 second Cir1 7 second Cir1 7 repeat Cir1 8 begin Cir1 8 second